INVESTIGATION OF POLYETHER AND POLYETHER COMPOSITES AS 
ELECTROLYTES FOR ADVANCEMENT TOWARDS LITHIUM METAL BATTERIES 

By 

Shaylynn Crum-Dacon 

A DISSERTATION 

Submitted to 
Michigan State University 
in partial fulfillment of the requirements   
for the degree of 

Chemical Engineering – Doctor of Philosophy 

2023 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ABSTRACT 

Epoxides, polyether precursors, are favorable materials for many applications. They have a ring 

strain that promotes polymerization, diverse functionalities, and are relatively easy to synthesize 

through sustainable means. Although epoxide polymerization can be traced back a few decades, it 

wasn’t until 2017, when published work by Ferrier reported using mono(μ-

alkoxo)bis(alkylaluminum) (MOB) to quickly and easily polymerize different epoxides. This 

polymerization platform will be used to explore polyether-based single-ion conductor electrolytes 

in the first work. Polymer electrolytes are said to be the future for lithium batteries. By replacing 

the anodic materials with solid lithium (making a lithium metal battery) and the organic solvent 

media with a polymer, the high functioning lithium metal’s properties will increase battery 

efficiency. This project will dive into utilizing poly(epichlorhydrin) (PECH) and poly(propylene 

oxide) (PPO) to synthesize a single-ion conducting electrolyte. This work reveals synthesis of the 

single-ion conductor (SIC) using bis(trifluoromethanesulfanamide) as the single-ion conducting 

moiety. The incorporation of PPO combats the crystallinity of PECH, which is shown by Tg 

analysis and ionic conductivity. The knowledge gained from this research will be valuable in 

moving forward for solid state electrolytes for lithium metal battery applications. 

Polymer composites are currently the most popular way to advance electrolyte matrices within 

lithium batteries, as they can eliminate the adverse properties of polymers (i.e. crystallinity and 

low ionic conductivity) by employing filler (solvents, ceramics, carbon powders, etc.) materials 

within the matrix to improve properties for desired applications. With intentions to incorporate the 

previous project, this work focuses on utilizing polyether-grafted nanoparticles (NPs) 

incorporated in a polyether matrix to study ether composites for LMB applications. An initiator 

was grafted onto the surface of the NPs and ECH was polymerized from the site. We alleviate 

compatibility concerns by using a low molecular weight ether matrix with a high molecular 

ii 

 
weight ether filler as well as explore possible electrolyte applications and combinations with the 

ether SIC. 

The final project is intended to further epoxide use and application by expanding possible 

polymerization methods inspired by MOB synthesis. This work utilizes primary and secondary 

amine compounds to synthesize polymerization platforms. This introductory study revealed 

simplistic synthesis of different amine initiators that could be used in tandem with the N-Al 

adduct to polymerize epoxides with different functionalities. These platforms will be utilized to 

explore different pathways for synthesizing polymer and composite electrolytes for lithium 

battery applications.  

iii 

 
 
 
 
 
 
 
 
 
 
 
 
This is for Deshawn, Eshlawn, Lil Mama, and her friends…LOL Just Playing! 
Well almost… 
It’s for every little black girl who didn’t know the sky was the limit until she started reaching 
for the clouds. 
It’s for the bravery to try things that you’ve never known, win or lose. 
It’s for believing in yourself… 

iv 

 
 
 
ACKNOWLEDGEMENTS 

I want to thank my advisor, Dr. Robert Ferrier, for allowing me to be a part of the Ferrier group 

and for the all the guidance during my doctoral studies. Thank you extending patience for my 

random office pop-ups and stupid questions. You offered endless support and understanding 

during this time in my life. It has been an honor being able to participate in research and learn 

from you. I want to extend my gratitude to the ChEMS department for the support and resources. 

The staff has always been extremely helpful for anything I needed. You are a group of people that 

get things done. I would also like to thank my committee, Dr. Shiwang Cheng, Dr. David Hickey, 

and Dr. Greg Swain for reviewing my work and providing constructive criticism. Thank you for 

extending patience for my random office pop-ups and answering every small and large question I 

ever asked. To Dr. Joseph Dumont, my LANL mentor and pillar of realness, thank you for 

grounding and supporting me. Thank you for pushing me past my fears. For everyone mentioned, 

thank you all for constantly pushing me to be the best version of myself and helping me achieve 

my goals. 

I would like to thank my MSU community for extending additional comforts for my acclimation. 

Mayson and Harrison, I am not sure how I would’ve made it without you guys, especially our first 

year. To my lab and office mates (old and current), Niloofar, Gouree, Geetanjali, Danielle, Chase, 

Lincoln, and Sunanda thank you for your guidance, suggestions, listening ears and laughs. They 

were always well needed and came just in time.  

Lastly, I would like to thank my loved ones, my family, best friends, and husband. TaShara (Tee), 

Alyssa (Lee), Loretta (Lo), Kieara (Kee), Kiana (Key), and Nia (Ni), thank you for hearing my 

endless complaints, talking me from the edge (proverbial, lol) and always reminding me who I am 

and my capabilities. The years of support mean the world to me. To whom started as a friend, then 

v 

 
boyfriend, and now husband, I owe you so many thanks. Like, literally thanks for everything. For 

helping me with my anxiety, to constant encouragement, feeding me to holding me when I cry. 

You have been my rock since you walked past me wearing that very, very, very fragrant cologne 

Spring 2019. Lol. I am excited for our new adventure. 

In conclusion, y’all really held me down and for that, you will always have my gratitude and love.   

vi 

 
 
 
TABLE OF CONTENTS 

INTRODUCTION .......................................................................................................................... 1 
Polyethers & Applications ........................................................................................................... 1 
Epoxide Polymerization .............................................................................................................. 2 
Lithium Metal Batteries .............................................................................................................. 5 
Thesis Summary .......................................................................................................................... 6 

SYNTHESIS FOR POLYETHER-BASED SINGLE-ION CONDUCTORS FOR LITHIUM-ION 
TRANSPORT ................................................................................................................................11 
Introduction ............................................................................................................................... 13 
Experimental Section ................................................................................................................ 14 
Results ....................................................................................................................................... 20 
Conclusion ................................................................................................................................. 29 
Future Work ............................................................................................................................... 29 

UTILIZING ETHER GRAFTED CERAMIC NANOPARTICLES FOR POLYETHER 
COMPOSITE ELECTROLYTE SYNTHESIS ............................................................................ 31 
Introduction ............................................................................................................................... 32 
Experimental Section ................................................................................................................ 34 
Results ....................................................................................................................................... 41 
Conclusion ................................................................................................................................. 46 
Future Work ............................................................................................................................... 47 

EXPLORING AMINE-BASED INITIATORS FOR EPOXIDE POLYMERIZATION .............. 48 
Introduction ............................................................................................................................... 49 
Experimental Section ................................................................................................................ 50 
Results ....................................................................................................................................... 53 
Conclusion ................................................................................................................................. 55 
Future Work ............................................................................................................................... 56 

CONCLUSION ............................................................................................................................. 57 

FUTURE WORK .......................................................................................................................... 59 

REFERENCES ............................................................................................................................. 61 

APPENDIX ................................................................................................................................... 66 

vii 

 
 
 
Polyethers & Applications 

INTRODUCTION 

Polyethers are the result of the polymerization of three membered heterocyclic rings called 

epoxides. Due to the ring strain of the monomers, these compounds are prone to ring opening 

with minimal effort, making them easy to polymerize.1 Polyethers are popular in many 

applications due to their biocompatibility, thermal transitions and hydrophilic nature as a result 

of their backbones. While the backbones already offer a great deal of desirable qualities further 

functionalization via pendant groups pre- and post-polymerization can further tune properties for 

intended applications. Poly(ethylene glycol) (PEG) is the most utilized polyether to date. It is the 

product of polymerizing ethylene oxide and is used in food, cosmetics, and more. Polyethers are 

also in polyurethane foams which are major components in insulation and cushions for seats and 

mattresses).2 Functionalized polyethers can also lead to a multitude of idyllic performing 

materials for drug-delivery3, battery electrolytes4, food and antifouling coatings5,6, separation 

membranes7, and even anti-counterfeiting applications8. The possibilities for polyether 

Figure 1:Figure of Common Polyether Applications 

applications continue to grow every day, proving them to be a superior material for scientific 

innovations. 

1 

 
Epoxide Polymerization 

History 

Epoxide polymerization has been around since the late 1800’s. Wurtz was one of the first to 

document ethylene oxide (EO) polymerization by utilizing metal hydroxides and zinc chloride to 

drive the anionic ring-opening polymerization (AROP) in 1863.9 In 1933, Staudinger introduced 

a high molecular weight poly(ethylene oxide) via AROP for the first time.10 Poly(ethylene 

glycol), a water-soluble and biocompatible epoxide derivative, was commercialized in the 1930s 

via EO addition under basic conditions. From then on, the application range of these epoxides 

have expanded to include endless applications such as household uses - detergent, construction - 

lubricants, drug delivery and the beauty industry.1112 Ten years later (1940’s), Flory introduced 

living chain growth polymerization after proving EO propagation occurrence without side 

reactions by using a base-initiated polymerization.13 These foundational methods are the reason 

the following decades were able to discover and mass produce epoxides and their derivatives for 

their desirable properties in a multitude of fields and applications.  

Methodology 

Since the introduction of EO polymerization methods in 1863, there has been quite a bit of 

research dedicated to successfully polymerize a multitude of polyethers of varying molecular 

weights with relatively narrow polydispersities.14  AROP and cationic ROP techniques are 

common but they result in polyethers with minimal functionality and low molecular weights.15 

Vandenberg’s catalyst is also a popular method, but the technique lacks control when trying to 

produce high molecular weights with narrow polydispersities.16,17  

Although the traditional methods proved to be useful in some polymerizations, functional 

epoxides are typically more difficult to polymerize, limiting functional polyether material 

2 

 
development for many applications. Lynd and Ferrier reported creating a one-pot, one step 

polymerization system, mono(μ-alkoxo)bis(alkylaluminum) (MOB) that allows for a controlled 

polymerization of functional epoxides. The mechanism utilizes ionic and catalytic approach that 

follows coordination insertion without chain transfer affecting functionality. Research shows that 

this system can polymerize various epoxides with different functional groups, such as 

chloromethyl, alkenes, and alkynes groups. MOB is extremely fast compared to traditional 

methods and promotes the use of green chemistry because it polymerizes >98% of the epoxide 

and minimizes or removes the necessity of solvents for the reaction. 18,19 Furthermore, the initial 

materials are derived from renewable feedstocks (i.e. glycerin).20–22 Overall, the “green” 

advantages of the MOB platform make it an ideal method of epoxide polymerization as it 

includes faster reaction times at moderate or ambient temperatures without excessive use of 

solvent, decreases waste of reactant materials, and involves progressively sustainable primary 

reactant production. 

3 

 
Figure 2: Green Chemistry Principles  

The thesis work utilizes MOB to expand lithium-ion transport systems for battery applications. 

Epichlorohydrin (ECH), an epoxide that can be easily and quickly polymerized via MOB 

method, has a chloromethyl group that allows for post-polymerization tuning. Other 

functionalized epoxides with methyl and ethyl pendants can influence hydrophobicity, ion 

transport, and structural crystallinity/ chain flexibility. The epoxides with their functional groups 

will allow for an ideal electrolyte design. 

While MOB is extremely efficient, it is important to also investigate future platforms to expand 

the possibilities for ether applications. The earlier mentioned epoxides were also used to explore 

alternative platforms for epoxide polymerizations. Amines have been used in polymerization 

4 

 
platforms that are not unique to solely epoxides for decades.23,24  Amines with active protons are 

prone to react with metal complexes to a variety of compounds; cyclic amines could also act as 

catalyst-initiators for ROPs.25 We will utilize amine compounds to form simple and efficient 

polymerization platforms that can also explore unique structures. 

Lithium Metal Batteries 

In 1971, Dr. Stanley Whittingham and Dr. John Goodenough proposed the first rechargeable 

lithium ion battery (LIB), using titanium (IV) sulfide and lithium metal.26 However, this battery 

was impractical since the starting material, titanium disulfide, not only lacked in cost-efficiency 

but was also a safety hazard. This discovery catalyzed the massive interest in research focused on 

employing different materials to optimize LIBs. The first LIB was commercialized by Sony 

company in 1991, composed of graphite as the anode and lithiated cobalt oxide as the cathode.27 

Lithium-based batteries have since been used in consumer and military electronics, travel, and in 

the medical and industrial field as well. In 2019, Goodenough, Whittingham and Yoshino were 

awarded the well-deserved Nobel Prize in Chemistry for the development of lithium-ion 

batteries.28  

Figure 3: Lithium Metal Battery Schematic 

5 

 
With the world’s leading consumer-product battery to be lithium based, it is now the time to try 

to advance its configuration to promote sustainability alongside product evolution. Lithium metal 

batteries have solid lithium metal as anodes instead of the carbonaceous materials found in 

typical LIBs. Employing lithium metal as the anode shows promise as the metal’s lightweight 

and low-density nature could result in an increase conductivity and decrease costs by shortening 

distance of ion path and lessening weight as the entire battery takes up 55% of the weight of an 

electronic.29 Lithium also has a high theoretical specific capacity of 3860 mAh/g, outperforming 

the graphite-based anode currently in-use (400 mAh/g) and has a low standard negative potential 

of -3.04 V when compared to standard hydrogen electrode (S.H.E.). Standard negative potential 

quantifies the “solvability” of an electrode material. Although lithium metal is considered the 

“holy grail” for battery anodes, they have not been put in practical application due to risky and 

insufficient designs and material compatibility. The most pressing concern is lithium metal’s 

reactivity/ pyrophoric affinity with organic, liquid, and aqueous solvents usually utilized in liquid 

electrolytes in current LIBs. Lithium metal also has a tendency towards volume expansion and 

other unwanted ion interactions such as side reactions, dendrite formation, and anion 

polarization.30 

Thesis Summary 

For the first study, we exhibited the possibility of utilizing easily polymerized neat high and low 

molecular weight polyepichlorohydrin (PECH) as well as poly(epichlorohydrin-stat-propylene 

oxide) (P(ECH-stat-PO) )  for lithium ion transport. These polymers had relatively low glass 

transitions. These polymers were then used to synthesize a single ion conducting electrolyte that 

resulted in improved ionic conductivity. The relationship between the molecular weight/ polymer 

6 

 
composition and electro- and thermochemical properties of these samples was revealed, 

explaining how these parameters affect one another.  

Scheme 1: Single-Ion Conductor (SIC) Synthesis using PECH and P(ECH-stat-PO) 

Figure 4: Ionic Conductivity Analysis throughout SIC synthesis 

The next study showed the synthesis of a novel polymer composite that consists of a polyether 

matrix from the previously mentioned study and uniquely synthesized grafted nanoparticles 

(GNPs). The nanoparticles underwent a synthesis that attached an initiator (3-

aminopropyltrimethoxysilane, APTS) to the surface. This initiator later proved to be able to 

polymerize epoxides, and subsequently PECH for this study. The GNP with grafted PECH 

7 

 
 
(GNPNHPECH) showed improved thermal resistance and ionic conductivity. This work revealed 

composite composition-property relationships, taking into consideration weight percent (wt%) of 

incorporated GNPs, Tg, Td, and ionic conductivity.  

Scheme 2: Synthesis of Grafting the NP with APTS and polymerizing ECH 

Figure 5: (1) Thermal Degradation of PECH (7.5K, 30K, GNPNH10K, & GNPNH30K) and 
(2) Ionic Conductivity of GNPNHPECH of different GNP wt% 

The last study explored amine-based initiators to expand epoxide polymerization platforms for 

general studies and future composite applications. This study included benzylamine, N-

ethylethylenediamine, and 3-aminopropanol coupled with trimethyl aluminum. Although this 

8 

 
study is preliminary, evidence shows that the synthesized initiators when paired with the N-Al 

adduct were able to polymerize ECH, butylene oxide (BO), and propylene oxide (PO). This work 

needs to be expanded upon to investigate other epoxides, copolymers, and the reaction kinetics 

for each initiator.  

9 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 6: 1H and 13 C NMR of Proposed Initiator Structures 

10 

 
SYNTHESIS FOR POLYETHER-BASED SINGLE-ION 
CONDUCTORS FOR LITHIUM-ION TRANSPORT 

ABSTRACT 

Over 50 years ago, it was discovered that polymers can be utilized in energy storage as it was 

found that certain matrices allow for ion conduction. From then on, investigation into utilizing 

PEO and others commenced for energy storage. These studies can be connected to the evolution 

and widespread application of lithium-ion batteries (LIBs) today. Due to this generation’s heavy 

electronic use and innovations, there is now a much higher demand for more efficient and cost-

effective lithium batteries. In efforts to improve efficiency and sustainability, replacing current 

anodic material with solid lithium metal, evolving to lithium metal batteries (LMBs), can 

maximize efficiency within the battery system. Due to lithium metal’s high reactivity, LMBs can 

only be put in application with an electrolyte that can maintain stability and cationic mobility 

throughout the system while suppressing detrimental occurrences (e.g., dendrite growth, heat 

accumulation, anion polarization, solid-electrolyte interphase (SEI) destabilization, etc.). 

Replacing organic liquid electrolytes in current LIB configurations with solid state electrolytes 

like polymers could meet these requirements. Polyethers, like poly(ethylene oxide) (PEO), have 

already shown promise as polymer electrolytes due to the ether oxygen’s favorable interaction 

with Li ions and electrochemical stability. Unfortunately, low ionic conductivity prevents 

polyethers from being put into application. Functional polyethers or their monomers could be 

tuned to optimize ionic conductivity, but traditional polymerization or synthetic methods did not 

allow for constituent or controlled production. This work reveals the results from utilizing 

specially tuned polyether-based electrolytes which were synthesized through a novel aluminum-

based polymerization platform, developing polymer composition – electrochemical and 

thermophysical property relationships. We will accomplish this through investigation of 

11 

 
 
copolymers containing monomers with specific properties that are important to theoretical 

molecular weight, copolymer composition, ionic conductivity, and Tg. 

12 

 
 
 
Introduction 

Synthesizing a solid polymer electrolyte (SPE) could alleviate unease surrounding LMB use as 

they have the chemical and mechanical robustness to withstand the deleterious effects that the 

use of lithium metal may cause. Poly(ethylene oxide) (PEO), in the 1970’s, was revealed to 

display lithium ion conduction.31 Even though PEO has been studied for a half of a century, there 

is still hesitation in implementing the compound in battery applications without complicated 

synthesis or additional materials. The drawback from utilizing PEO as the primary matrix 

material is its semi-crystalline nature, which impedes chain flexibility and salt dissolution. This 

property has a direct correlation to low room temperature ionic conductivity. Nevertheless, its 

backbone composition of electronegative oxygens and desirable properties (high dielectric 

constant, chain flexibility, strong ion solvation, mechanical robustness) maintain its relevancy in 

electrochemical applications.32  

There has been a lot of work put into synthesizing SPEs, yet the majority tend not to meet the 

requirements for room temperature ionic conductivity (𝜎RT), 10-3 Siemens/cm. The typical SPE 

has a 𝜎RT of 10-4 Siemens/cm which can be attributed to poor ion dissociation, low lithium 

transference (tLi+)(<0.5) and low dielectric constant/ relative permittivity ( (<4).33,34  

We can navigate around these setbacks by creating a single-ion conductor, which is a polymer 

electrolyte that has an anion anchored to the backbone of polymer, leaving only the active cation 

13 

 
the mobile ion. This allows for Li+ to solely contribute to a permanent flow of charge, resulting 

Figure 7: Schematic of SIC 

in a tLi+ of 1.  

This work is dedicated to developing a polyether-based single ion conductor using ECH as the 

polymer matrix because of its relatively low Tg, and its functional chloromethyl group that 

allows for further functionality. Bis(trifluoromethanesulfanamide will be the single ion 

conducting anion, with chemical groups known to promote lithium mobility. PPO will also be 

used to combat Tg changes from anion addition. This electrolyte will have qualities that can 

bypass low tLi+, lithium metal’s reactivity, ion dissociation, and anion polarization for lithium 

metal battery applications. 

Experimental Section 

Materials: 

Triisobutylaluminum (TIBA) (1.0 M in hexanes, Sigma-Aldrich), dimethylaminoethanol 

(DMAE) (Sigma-Aldrich, >98%), trimethylaluminum (TMA) (2.0 M in hexanes, Sigma-

Aldrich), triethylamine (TEA) (Sigma-Aldrich) and anhydrous hexanes (Sigma-Aldrich >99%) 

were all used for preparing catalyst and initiator for polymerization of epichlorohydrin (ECH) 

(Sigma-Aldrich) and propylene oxide (PO) (Sigma-Aldrich) in glovebox without any 

14 

 
modification. Glovebox was used to carry out all moisture and oxygen sensitive reactions in 

nitrogen environment. 

Methanol (MeOH, Fisher, Certified ACS), hexanes (Fisher, Certified ACS) and dichloromethane 

(DCM) (Fisher, Certified ACS) were used to remove unreacted monomers and catalysts from 

polymer products.  

Bis(trifluoromethanesulfanamide) (TFSA) (Sigma-Aldrich >99%), anhydrous acetonitrile 

(ACN), TEA (Sigma-Aldrich), 4-dimethylaminopyridine (DMAP), were used for the addition of 

the anion amine pendant to the ether backbone. N-butyllithium (butLi) (0.1 M in hexane, Sigma-

Aldrich), lithium bis(fluorosulfonyl)imide (LiTFSI) (Sigma-Aldrich) and tetrahydrofuran (THF) 

(Sigma-Aldrich) were used for lithium-ion addition.  

Chloroform-d (Cambridge Isotope Laboratories, Inc. 99.8%), water-d2 (Cambridge Isotope 

Laboratories, Inc. 99.8%), and dimethyl sulfoxide-d6 (Cambridge Isotope Laboratories, Inc. 

99.8%) were used for preparing NMR samples without any alteration. 

Instrumentation: 

All (1H, 12C, 19F, 7Li) NMR spectroscopy was performed on Agilent DDR2 500 MHz NMR 

spectrometer using deuterated solvents at room temperature. The chemical shifts are reported in 

parts per million (ppm) and are referenced using the residual peak from the deuterated solvent. 

Differential scanning calorimetry (DSC) tests were administered on a TA250 instrument. The 

samples were cycled from -90°C to 150°C at a heating rate of 10°C min−1 under an N2 

atmosphere, and thermal data was taken from the third heating curve.  

FTIR analysis was completed using Shimadzu IRAffinity spectrometer with MIRacle ATR 

attachment. Sample conditions were set to 264 scans taken between the wavelength on 450-4000 

cm-1. 

15 

 
Samples were loaded in a Biologic Controlled Environment Sample Holder (CESH), consisting 

of two parallel anodized aluminum plates, a fixed bottom disc (47 mm diameter) with a 0.25” 

gold electrode installed, and a vertically mobile upper metallic plate. The ionic conductivity of 

the polymer electrolyte samples was measured by electrochemical impedance spectroscopy using 

a Biologic VSP potentiostat. The potential was set to an open circuit with an alternating potential 

of 10 mV amplitude and scanned from 1 Hz to 1 MHz frequency.  

The resulting spectra was then fit to the following equation as the circuit for ether samples 

analyzed in the CESH-e cell depicted below in Figure 8 where R2/Q2 models the bulk resistance 

and R1 and Q3 represents the conduction through the grain boundaries.  

Figure 8: Circuit for CESH-e cell with Ether Electrolyte Samples 

The bulk resistance (Rb or R2) was determined from the low-frequency x-axis intercept of the 

fitted Nyquist impedance plots, and ionic conductivity (𝜎) was calculated by the following 

equation.35 

𝜎 =  

𝑡
𝑅𝑏∗𝐴

Methods: 

(Eq. 1) 

Synthesis of triisobutylaluminum adduct of (2-dimethylamino)ethoxy-diisobutylaluminum (MOB) 

Approximately 13 mL of 1.0 M triisobutylaluminum in hexane (12.7mmol) was added to a 

reaction vial with a magnetic stirrer and cooled to –78ºC inside a glovebox under nitrogen 

atmosphere. To this vial, 0.5 mL of dimethylaminoethanol (4.7 mmol) was added dropwise. The 

16 

 
 
 
 
 
 
 
 
 
 
 
 
reaction was carried out by continuous stirring until it warms to room temperature overnight. The 

crystals were then washed with anhydrous hexanes three times to remove excess reactant and 

dried under vacuum.18 

 1H NMR (CDCl3, 500 MHz) δ 0.14 to -0.15 (m, –Al[–CH̲ 2–CH–(CH3)2]2, and m, –Al[–CH̲ 2–
CH–(CH3)2]3), 0.92 (m, –Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 1.82 (m, 
–Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 2.59 (s, N–(CH̲ 3)2), 2.87 (t, N–
CH2–CH2–O), 3.97 (t, N–CH2–CH̲ 2–O)  

Scheme 3: Synthesis of MOB 

General procedure for polymerization using MOB 

Figure 9: 1H NMR of MOB 

All polymerizations were performed in a septum-capped 20 mL reaction vial under inert 

atmosphere in a glovebox. The vials were charged with a stir bar, monomer(s) and initiator-

17 

 
catalyst for a targeted amount of 5 g of the final polymer weight. MOB amount was dependent 

on the targeted molecular weight and resulting moles, as the kinetics for this system accounted 

for a 1 mol MOB:1 mol polymer for desired polymerization. The copolymer solutions had to be 

heated to a reaction temperature of 50°C. All polymerizations were carried out for 5 hours-3 days 

(until its >90% polymerized). Reactions were quenched with methanol and dissolved in DCM to 

remove aluminum. The resulting solution was added dropwise into MeOH to precipitate out the 

desired polymer product. The polymer was first dried using rotary evaporator and then kept 

under vacuum overnight to remove residual solvent. 

Four neat polymer samples were polymerized using MOB. The first three samples had a targeted 

molecular weight of 30,000 g/mol with PECH mole percent being 100%, 75%, and 50%. The 

last sample was 100% PECH with a 7,500 g/mol targeted molecular weight.  

Scheme 4: PECH and P(ECH-stat-PO)polymerization using MOB 

Synthesis of Polyether-Based Single-Ion conductor (PESIC) 

Following the synthesis methodology from Bocharova et al, approximately 2.5 g of the neat 

polymers were dissolved in 10 mL of dried CH3CN and immersed in an ice bath.36 One g of 

TFSA, 7 mL TEA, and 0.2 g DMAP were dissolved in 20 mL of dried CH3CN; from that 

18 

 
mixture, 5 mL were added to the solution of the polymerized samples. After stirring for 2 hours 

in an ice bath, the mixture was stirred at room temperature overnight. The solvent was removed 

by rotary evaporation, and the products were redissolved in 15 mL of DCM. The solution was 

washed through an aqueous solution of NaHCO3 (2%, 3×35 mL), then HCl (1 mol/L, 4×30 mL). 

The products were then precipitated out with hexanes. The supernatant was removed from the 

vial; then, the solvent was removed via rotary evaporation and dried under vacuum. 

Lithiating PESIC Samples 

The lithiation of the samples occurred in a controlled environment under nitrogen atmosphere. 

Approximately 1 g of the cleaned PESIC samples were dissolved in THF and cooled to -50°C 

and 0.5 mL of n-butyllithium was added dropwise to the cooled solution then returned to the cold 

well and stirred overnight. 37 Sample was precipitated with hexanes and dried via rotary 

evaporation. The samples were dissolved in DCM and precipitated and dried again. 

Scheme 5: Single-Ion Conductor (SIC) Synthesis using PECH and P(ECH-stat-PO)  

Sample Prep for EIS Testing 

Portions of the neat polymer, PESIC, and PESIC-Li+ for all polymers and copolymers were 

dissolved in THF and the corresponding amounts of LiTFSI were added to achieve 

[EO]/[Li]=10. Rotary evaporation removed most of the solvent, and the samples were placed in 

the oven at 55°C for 48 hours afterwards. 

19 

 
Results 

Glass Transition Temperature Analysis: 

Tg Prediction Using Fox Equation 

Figure 10: Tg prediction of P(ECH-stat-PO)  

Earlier synthesis revealed a major Tg increase for the SIC samples, making them inoperable at 

RT and impossible to analyze electrochemically. Incorporating PO into the polymer matrix 

lowered the Tg enough to combat the increase from attaching the anion moiety. To determine the 

ideal PO% that should be incorporated into the SIC, DSC experiments were performed to 

understand Tg change with PO percent of P(ECH-stat-PO) . For homopolymer of high molecular 

weight PECH Tg is -26°C and for homopolymer of PPO Tg is -67°C. The resulting Tg of a 

statistical copolymer would be a combination of the two polymers. This can be fitted using Fox 

equation as a function of PO composition. Ensuring that the theoretical Fox Tg is appropriate for 

this system allows for the prediction of Tg for future work in applications for similar systems. 

The Fox equation is based on the Flory-Fox theory which correlates molecular weight to Tg and 

is based on the concept of “free volume.” With Flory-Fox, Tg is considered as the temperature at 

20 

 
which free space becomes available and that each monomer will occupy the same amount of free 

volume. The Fox equation is based on the concept that additive/plasticizer presence increases 

“free volume,” and consequently, good for predicting Tg in miscible polymer blends and 

statistical copolymers, and therefore, preferred for this research.  

1
𝑇𝑔

=  

𝑥1
𝑇𝑔,1

+  

𝑥2
𝑇𝑔,2

(Eq. 2) 

𝑇𝑔 is glass transition temperature of combined components, and xi and 𝑇𝑔,𝑖 are mole fraction and 

glass transition of component i, respectively. Although from Fig. 10, the numbers are not exact, 

they are comparable enough to be useful. This method will allow for future Tg approximation of 

the statistical copolymers that will be used for this research without having to go completely go 

through synthesis and analysis. 

Tg Evolution Throughout PESIC-Li+ Synthesis  

It is well-known that the Tg heavily affects ion mobility for polymer-based electrolyte systems, 

so it is important to monitor the change in Tg throughout the multi-step synthesis. In Fig. 11, the 

system also exhibits Flory-Fox behavior mentioned in the previous paragraph which attributes to 

the reasoning why the lower molecular weight PECH has a lower Tg when compared to the other 

samples as it has more free volume.38 The higher the Mw the less space there is for each chain to 

move. Subsequently, 7.5K sample has the lowest Tg at -46°C and the 30KPECH sample has the 

highest at -31°C. The 75PECH and 55PECH had Tg temperatures of -36°C and -42°C. The 

samples all showed a minor increase in Tg after the TFSA addition to the backbone as a result the 

addition of the amine moiety increasing chain rigidity.36 The lithiation of the samples resulted in 

a negligible shift in Tg (±2°C). DSC analysis revealed the Tg shift throughout the synthesis can 

be considered minimal for this specific system and synthesis. It is also pertinent to understand 

21 

 
  
 
 
 
 
 
 
 
 
 
that varying the molecular weight of PECH samples and copolymer-SIC composition will not 

reflect identical trends in similar analysis. 

Figure 11: Tg Evolution Throughout SIC Synthesis 

Chemical Characterization: 

NMR Analysis 

The neat 30K and 7.5K PECH were dissolved in CDCl3 for NMR analysis. The ether backbone 

resides at δ 3.8 – 3.5 in the 1H NMR spectra. For the 12C NMR, the methine, Cl-bonded 

methylene, and methylene were recorded at δ 79, δ 43.7 and δ 69.5, respectively. After adding 

the moiety, the samples were dissolved in DMSO, the amine proton (δ 8.95) was revealed by 

using a D2O exchange and the ether backbone range shifts, δ 3.8 – 3.4. The methine, methylene, 

and N-bonded methylene for the 12C NMR had minute changes when compared to the precursor 

polymer. 

22 

 
 Figure 12: 1H NMR of Neat PECH and Polyether SIC (PESIC) 

Figure 13: 13C NMR of Neat PECH and Polyether SIC (PESIC) 

23 

 
 
The neat 75 and 55PECH samples were dissolved in CDCl3 for NMR analysis and after adding 

the moiety, the samples were dissolved in DMSO. The ether backbone resides at δ 3.8 – 3.4 and 

the methyl group appears at δ 1.1 in the 1H NMR spectra. For the 12C NMR, the PECH and PPO-

methine groups were recorded at δ 79 and δ 76, respectively. The PECH and PPO backbone 

methylene groups were found at δ 70 and δ 74, respectively. PPO methyl group was recorded at 

δ 17. The Cl-bonded and N-bonded methylene were found at δ 43 and δ 45, respectively. The 

amine proton (δ 8.95) was revealed by using a D2O exchange and the ether backbone range is 

essentially the same. Although there is a noticeable change in the peak splitting after the 

substitution, due to the repeating bonds it is difficult to determine which protons are from PECH 

or PPO. It is also important to note that these statistical polymers do not have an even 

distribution of monomer units, so the system is not entirely uniform, making anything beyond 

monomer unit quantification difficult. The 12C NMR post-functionalization seems to have 

identical peak responses for the species as the neat polymer.  

24 

 
 
Figure 14: 1H NMR of Neat P(ECH-stat-PO) and Polyether SIC (PESIC) 

Figure 15: 13C NMR of Neat p(ECH-stat-PO) and Polyether SIC (PESIC) 

25 

 
 
Fluorine NMR spectroscopy was also used to verify the presence of the SIC anion. The peak for 

CF3 group appears at δ -78 ppm. 7Li NMR spectroscopy was also employed, and it showed a 

singlet at δ -0.85 ppm that fell in the range of aqueous lithium, proving the presence of Li+. 

Proton and 1H and 12C NMR tests were also ran for this sample and the lack of butyl protons and 

carbons confirmed that only Li+ remained in the system after cleaning.  

 Figure 16: 19F NMR of Neat (1) PECH-SIC and (3) p(ECH-stat-PO) SIC and 6Li NMR of Neat 
(2) PECH-SIC and (4) p(ECH-stat-PO) SIC 

26 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
FTIR Analysis 

Figure 17: FTIR spectra of neat p(ECH-stat-PO) SIC throughout synthesis 

FTIR spectra has shown successful attachment to the polymer backbone and lithiation. N-H 

bonds appear at 3300 cm-1 after synthesis. There is also a peak at 1600 cm-1 that represents C-N 

connection and CF3 peak appears at 1200 cm-1. The sulfate signal is not evident due to the C-O-C 

bond from the polymer backbone at 1100 cm-1, as the group is reported to appear in that same 

region. The peak appearance >500 cm-1 represents Li+ interaction/coordination. The -OH bonds 

are most likely due to the hygroscopic nature of the sample. 

27 

 
 
 
 
 
 
Ionic Conductivity Study: 

Figure 18: Ionic Conductivity Analysis throughout SIC synthesis 

Figure 18 shows the room temperature ionic conductivity of the ether samples. To understand 

how the addition of the SIC unit and manually added lithium affected the conductivity, LiTFSI 

was also added to the matrix to promote conductivity. The semi-crystalline nature of PECH 

prevented good ion conduction within the 30KPECH and 75PECH samples, so there are only 

lithiated SIC values and polymer SIC conductivity values for 30KPECH and 75PECH, 

respectively.39 The 55PECH sample shows increasing conductivity throughout synthesis and 

LiTFSI addition until the final polymer-SIC Li+. That decrease in conductivity value could be 

because of the decrease in lithium mobility because of the lack of free volume. The 7.5KPECH 

sample has shown constant increase in conductivity throughout synthesis and with lithium salt 

addition. The increased amount of free volume allows for the SIC and Li+ addition and LiTFSI to 

coordinate more uniformly the preceding samples. It is pertinent to look at lithium transference 

in the future as studies have shown that resulting conductivity could be due to increase in lithium 

ions versus actual ion mobility.40 

28 

 
Conclusion 

Past published works have revealed that utilizing polyethers for ion conduction in battery 

operations was possible if they were put into combination with organic solvents and or operated 

at high temperatures. This is due to the difficulty of maintaining ion mobility because of the 

semi-crystalline nature of the polymer, mechanical stability over time, or lack of consistent and 

controlled ion dispersion. 

The goal of this work was to attempt to utilize favorable polymeric matrices as single-ion 

conductors to contribute to the expansion of LMBs. These functionalized ethers which until the 

past few years were difficult to synthesize exhibited promising thermochemical properties. Here, 

we successfully polymerized polyethers in high and low molecular weight using MOB system. 

Those polymers were then tuned by adding an amine anion that underwent cation exchange to be 

a lithium-ion carrier. The results revealed that utilizing high molecular weight polyethers after a 

relatively simple modification can be used as a functioning electrolyte. Thermal properties were 

proven to be controlled and consistent throughout synthesis. SICs could have a promising future 

in LMB applications. By removing the free-flowing anion and anchoring it to the polymer 

backbone and substituting lithium salt by manually adding Li+ to a system, electrochemical 

properties were shown to compete with the former configuration for higher molecular weight 

samples. The lower molecular weight sample allows for a more flexible matrix that is more 

accepting of additional species that could promote Li+ mobility. 

Future Work 

The next steps for the work presented in this chapter includes exploring electrochemical window, 

investigating lithium transference, and expanding molecular weight variation. The 

electrochemical window (ECW) will reveal limiting operating voltage range for these 

29 

 
electrolytes as it entails the potential range where the electrolyte does not participate in redox 

reactions. We can understand the affect composition has on ECW, and subsequently electrolyte 

stability. We will also investigate Li+ transference to quantify the amount of lithium moving 

throughout the electrolyte as well as correlate lithium mobility to the electrolyte composition. 

The results revealed a lower molecular weight influenced higher ionic conductivity, but higher 

molecular weight matrices result in a more robust polymer. Expanding on the composition study, 

the molecular weight needs to be adjusted to find the optimal molecular weight.  

30 

 
 
 
UTILIZING ETHER GRAFTED CERAMIC NANOPARTICLES FOR 
POLYETHER COMPOSITE ELECTROLYTE SYNTHESIS  

ABSTRACT 

Composites are in our everyday products from packaging to automobiles. As technology 

progresses, composites have been the shining star for many applications. Composites have 

replaced many primary car frame materials, food storing and packaging options, and battery 

materials. Primary disadvantages of using composites are the difficulty creating consistent and 

uniform synthesized products. Due to unique interactions per composite materials and material 

of application, understanding the advantages and disadvantages for material use of composite 

configuration requires extensive research. 

This work reveals the results from utilizing specially tuned polyether-based composite 

electrolytes which had a two-part synthesis. The matrices utilized were neat polyethers and 

polyether-based single-ion conductors that were synthesized through the novel aluminum-based 

polymerization platform (MOB), mentioned in the previous work. The filler was comprised of 

silica nanoparticles (NPs) that were grafted with an amine initiator that polymerized ECH. The 

ether-grafted NPs (GNPNHPECH) have shown improvement against thermal degradation and 

consistent glass transition when compared to MOB polymerized PECH. Chemical and 

electrochemical characterization was also analyzed to confirm synthesis and understand the 

effect of creating this composite on additional properties.  The results assist in understanding 

ether composite material compatibility and developing polymer composition –property 

relationships.   

31 

 
 
 
 
Introduction 

Composites can be considered as an assembly of two or more materials that exhibit superior 

properties when together than the individual components. Composite materials are commonly 

called reinforcement arrangements or fillers that are embedded in a matrix.41 The matrix ensures 

cohesion, allowing typically incompatible materials to be utilized in the same capacity. The 

resulting composite can be heterogeneous and anisotropic.42 The nature of the matrix and the 

application materials, the interface, and the production process can influence the properties of the 

composite. 43 The matrix and filler material have a wide range of options that can include 

metallics, ceramics or plastics, allowing for a multitude of combinations.44 For composite 

materials, components with complementary physical and mechanical properties are combined to 

improve thermomechanical or chemical properties.45  

Current composites applications include packaging, automotive, biomedicine, and aerospace 

industries. Automotive and aerospace industry uses composites for body frame and under the 

hood materials as it has shown that substituting traditional materials to more lightweight and 

more sustainably produced options will improve efficiency and decrease harmful environmental 

impact.46,47 Biomedical inventions such as contacts and drug/supplement capsules are also 

composed of polymer composites which have been into application for decades.48 The packaging 

industry uses composites in a multitude of products including food, electronics, toys, and other 

consumer products.49  

Composite polymer electrolytes (CPEs) have been utilized in ion transport for battery and 

membrane applications for decades. For all ion transport applications, they offer favorable 

properties as the material selection is vast and is chosen based on desired properties for the 

product. CPEs are a polymer matrix with plasticizers or fillers that improve electrochemical and 

32 

 
mechanical properties. There have been multiple studies showing that synthesizing a CPE by 

chemical or physical means can have a positive effect on targeted properties for electrolyte 

application for lithium batteries. The presence of inorganic fillers has shown to improve 

electrochemical and thermal stability and ionic conductivity.50  Works revealed that altering the 

surface of silica nanoparticles can inhibit dendrite growth, enhance the Li+ mobility, and ionic 

conductivity. 51,52,53 

In this study, we synthesize silica nanoparticles grafted with an initiator that allows for epoxide 

polymerization; subsequently, grafting the surface of the nanoparticles with polyether chains. 

The purpose of this work is to utilize the methodology and intents from the previous chapter to 

expand upon further possibilities for LMB electrolyte applications. This work investigates the 

compatibility and benefits of ether-based polymers and grafted nanoparticles to correlate the 

composite structure and property relationships. The work will contribute to expanding single ion 

conducting electrolyte synthesis by attempting to further improve conductivity and mitigate 

dendritic formation which are pressing concerns for LMB application. We hope to incorporate 

Figure 19: Schematic of Proposed Polyether Composite 

the previous ether electrolyte composition in future studies as well. Here, we attach 3-

(aminopropyl)trimethoxysilane (APTS) to the surface of dispersed silica nanoparticles to create 

an initiator; then we polymerize ECH from the surface as the starting filler materials and a lower 

33 

 
molecular weight PECH as the matrix. We confirm synthesis as well as analyze thermal analysis 

and preliminary electrochemical properties of this ether composite. 

Experimental Section 

Materials: 

Triisobutylaluminum (TIBA) (1.0 M in hexanes, Sigma-Aldrich), dimethylaminoethanol 

(DMAE) (Sigma-Aldrich, >98%), trimethylaluminum (TMA) (2.0 M in hexanes, Sigma-

Aldrich), and hexanes (Sigma-Aldrich >99%) were all used for preparing catalyst and initiator 

for polymerization of epichlorohydrin (ECH) (Sigma-Aldrich) in glovebox without any 

modification. Glovebox was used to carry out all moisture and oxygen sensitive reactions in 

nitrogen environment. 

Methanol (MeOH, Fisher, Certified ACS), hexanes (Fisher, Certified ACS) and dichloromethane 

(DCM) (Fisher, Certified ACS) were used to remove unreacted monomers and catalysts from 

polymer products. 

Silica nanoparticles (NPs) (40-50 nm in Methyl Ethyl Ketone, Sigma-Aldrich), 

dimethylformamide (DMF) (Sigma-Aldrich), benzene (Bn) (Sigma-Aldrich), APTS(97%, 

Sigma-Aldrich), TMA (2.0 M in hexanes, Sigma-Aldrich) were used to synthesize the initiator-

grafted nanoparticle.  

Lithium bis(fluorosulfonyl)imide (LiTFSI) (Sigma-Aldrich) and tetrahydrofuran (THF) (Sigma-

Aldrich) were used for lithium-ion addition.  

Chloroform-d (Cambridge Isotope Laboratories, Inc. 99.8%), water-d2 (Cambridge Isotope 

Laboratories, Inc. 99.8%), and dimethyl sulfoxide-d6 (Cambridge Isotope Laboratories, Inc. 

99.8%) were used for preparing NMR samples without any alteration. 

34 

 
 
Instrumentation: 

All (1H, 12C, HSQC, GCOSY) NMR spectroscopy was performed on Agilent DDR2 500 MHz 

NMR spectrometer using deuterated solvents at room temperature. The chemical shifts are 

reported in parts per million (ppm) and are referenced using the residual peak from the 

deuterated solvent. 

Differential scanning calorimetry (DSC) tests were administered on a TA250 instrument. The 

samples were cycled from -90°C to 150°C at a heating rate of 10°C min−1 under a N2 

atmosphere, and the thermal data was taken from the third heating curve.  

Thermogravimetric Analysis (TGA) was performed using a TGA 500 (TA Instruments, USA). 

Each sample was heated to 800 °C with a heating rate of 10°C /min. 

FTIR analysis was completed using Shimadzu IRAffinity spectrometer with MIRacle ATR 

attachment. Sample conditions were set to 264 scans taken between the wavelength on 500-4000 

cm-1. 

Samples were loaded in a Biologic Controlled Environment Sample Holder (CESH), consisting 

of two parallel anodized aluminum plates, a fixed bottom disc (47 mm diameter) with a 0.25” 

gold electrode installed, and a vertically mobile upper metallic plate. The ionic conductivity of 

the polymer electrolyte samples was measured by electrochemical impedance spectroscopy using 

a Biologic VSP potentiostat. The potential was set to an open circuit with an alternating potential 

of 10 mV amplitude and scanned from 1 Hz to 1 MHz frequency.  

The resulting spectra was then fit to the following equation as the circuit for CESH ether-based 

samples is depicted below in Figure 20 where R2/Q2 models the bulk resistance and R1 and Q3 

represents the conduction through the grain boundaries.  

35 

 
Figure 20: Circuit for CESH-e cell with Ether Electrolyte Samples 

The bulk resistance (Rb or R2) was determined from the low-frequency x-axis intercept of the 

fitted Nyquist impedance plots, and ionic conductivity (𝜎) was calculated by the following 

equation. 

𝜎 =  

𝑡
𝑅𝑏∗𝐴

Methods: 

(Eq. 1) 

Synthesis of trimethylaluminum and triethylamine adduct (NAl Catalyst) 

A reaction vial was charged with a stir bar and 6.35 mL of 2.0 M trimethylaluminum in hexane 

(6.35 mL, 12.7 mmol) was added and cooled to –78ºC in a dry nitrogen glovebox. To this vial, 1 

mL triethylamine (12.7 mmol) was added slowly. The solution was set to stir and warm to room 

temperature overnight. These crystals were then washed with anhydrous hexanes three times to 

remove excess reactant and dried under vacuum.  

1H NMR (CDCl3, 500 MHz) δ -0.89 (s, Al–CH3), 1.03 (t, N–CH2–CH3), 2.53 (q, N–CH2–
CH3) 13C NMR (CDCl3, 125 MHz) δ 9.2 (Al–CH3), 46.25 (N–CH2–CH3), 47.79 (N–CH2–
CH3). 

 Scheme 6: Synthesis of NAl Adduct 

36 

 
 
 
 
 
 
 
 
 
 
 
 
 Figure 21: 1H and 13C NMR of NAl adduct 

Synthesis of triisobutylaluminum adduct of (2-dimethylamino)ethoxy-diisobutylaluminum(MOB) 

Approximately 13 mL of 1.0 M triisobutylaluminum in hexane (12.7mmol) was added to a 

reaction vial with a magnetic stirrer and cooled to –78ºC inside a glovebox under nitrogen 

atmosphere. To this vial, 0.5 mL of dimethylaminoethanol (4.7 mmol) was added dropwise. The 

reaction was carried out by continuous stirring until it warms to room temperature overnight. 

These crystals were then washed with anhydrous hexanes three times to remove excess reactant 

and dried under vacuum.18 

1H NMR (CDCl3, 500 MHz) δ 0.14 to -0.15 (m, –Al[–CH̲ 2–CH–(CH3)2]2, and m, –Al[–CH̲ 2–
CH–(CH3)2]3), 0.92 (m, –Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 1.82 (m, 
–Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 2.59 (s, N–(CH̲ 3)2), 2.87 (t, N–
CH2–CH2–O), 3.97 (t, N–CH2–CH̲ 2–O)  

 Scheme 7: Synthesis of MOB 

37 

 
 Figure 22: 1H and 13C NMR of MOB 

General procedure for polymerization using MOB 

The polymerizations were performed in a septum-capped 20 mL reaction vial under inert 

atmosphere in glovebox. The vials were charged with a stir bar, monomer(s) and initiator-

catalyst for a targeted amount of 5 g of the final polymer weight. MOB amount was dependent 

on the targeted molecular weight and resulting moles, as the kinetics for this system accounted 

for a 1 mol MOB:1 mol polymer for desired polymerization. All polymerizations were carried 

out for 5 hours (until its >90% polymerized). Reactions were quenched with methanol and 

dissolved in DCM to remove aluminum. The resulting solution was added dropwise into MEOH 

to precipitate out the desired polymer product. The polymer was first dried using rotary 

evaporator and then kept under vacuum overnight to remove residual solvent. 

1H NMR (CDCl3, 500 MHz) δ 2.97–3.53 (m, (–O–CH̲ 2–CH̲ (CH2–Cl)–O– 
13C NMR (CDCl3, 125 MHz) δ 43.71, 69.5, 79.02 

38 

 
 
Scheme 8: ECH polymerization using MOB  

Figure 23: 1H and 13C NMR of PECH 

Synthesis for Initiator Grafted Nanoparticles (GNPNH-MA) 

Centrifuging occurred at multiple steps throughout this synthesis and each run had the following 

conditions: 30,000 rpm for 15 minutes at the minimum acc/deceleration rate. NPs were received 

in MEK and to proceed with the reaction they needed to be dispersed in DMF. The MEK 

dispersed NPs were centrifuged, and the supernatant was removed. Approximately, 5 g of NPs 

were redispersed in 20 mL DMF and centrifuged 3 times afterwards to ensure the removal of 

MEK. With the NPs now in DMF, 5 mL of the NP in DMF was added to a charged 50 mL round-

bottom flask and approximately 1mL of APTS was added. The flask was then set to reflux at 

70°C for 4 hours. To remove reactants, the reaction mixture was centrifuged and dissolved in Bn 

after supernatant removal. It was centrifuged twice more and redissolved in Bn. The mixture was 

39 

 
poured into a reaction vial with a stir bar and purged with N2 before transferring to the glovebox. 

Then, 6.5 mL of TMA was added to the vial and left to stir overnight. 54 

General procedure for PECH polymerization using GNPNH-MA (GNPNHPECH) 

The polymerizations were performed in a septum-capped 20 mL reaction vial under inert 

atmosphere in glovebox. The vials were charged with a stir bar, 5-8 g of ECH, 1-2 mL initator-

GNPs and 50 mg of the N-Al adduct catalyst. All polymerizations were carried out for 24-72 

hours at 50°C (until its >90% polymerized). Reactions were quenched with methanol and 

dissolved in DCM to remove aluminum. The resulting solution was added dropwise into MeOH 

to precipitate out the desired polymer product. The polymer was first dried using rotary 

evaporator and then kept under vacuum overnight to remove residual solvent. 

Scheme 9: Synthesis of GNPNH and GNPNHPECH 

Sample Prep for EIS Testing 

Figure 24: Figure of Ether Composite (PECH + GNPNHPECH) Synthesis 

Portions of the neat polymer and GNPNHPECH for all polymers and copolymers were dissolved 

in THF and the corresponding amounts of LiTFSI were added to achieve [EO]/[Li]=10 to the 

matrix amount. GNPNHPECH were also added to achieve an NP wt % of 2.5 and 5. Rotary 

evaporation removed most of the solvent, and the samples were placed in the oven at 55°C for 48 

hours afterwards. 

40 

 
Results 

Chemical Characterization:  

NMR 

Figure 25: 1H NMR of GNPNH 

41 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 26: GCOSY NMR of APTS grafted NPs 

Figure 27: 1H NMR of GNPNH-MA 

The GNPNH was dissolved in CDCl3 for NMR analysis. The NH2 groups reside at δ 8.25, and 

the remaining protons at δ 1.35 – 1.1. The propyl group protons were verified by GCOSY. After 

42 

 
adding the TMA, the methyl groups from the reacted aluminum appear at δ 0.69. Due to the 

unreacted compounds remaining, the other protons are masked as the unreacted TMA peaks are 

in the same region.  

FTIR 

Figure 28: FTIR Stacked spectra of 30KPECH polymerized by MOB (black), GNPNH30kPECH 
(burgundy), GNPNH10KPECH (red) 

Fig. 28 shows the resultant spectra from the GNPNHPECH and both high and low molecular 

weights compared to 30KPECH polymerized from MOB. FTIR spectra has shown successful 

PECH synthesis. Due to intense peaks belonging to PECH, the initiator is mostly masked. The 

peaks at 3300 cm-1 are -OH bonds that are unreacted groups from the surface of the silica 

nanoparticles. There is a small peak indicative of the Si-O-Si stretching at 1050 cm-1. The signal 

is not evident due to the C-O-C bond from the polymer backbone at 1100 cm-1.  

43 

 
 
 
 
 
 
 
Thermal Analysis:  

Glass Transition 

Figure 29: Stacked Tg of 7.5KPECH (black) and 30KPECH (gray) polymerized by MOB, 
GNPNH10kPECH (red), GNPNH30KPECH (blue) 

In Fig. 29, the system exhibits Flory-Fox behavior mentioned in the previous paragraph which 

attributes to the reasoning why the lower molecular weight PECH has a lower Tg when compared 

to the other samples as it has more free volume.38 MOB polymerized samples of 7.5KPECH and 

30KPECH have glass transition temperatures of -46°C and - 31°C, respectively. The 

GNPNH10KPECH sample has lower Tg at -35°C the 30K sample has a Tg at -27°C. Overall, the 

Tg between all the samples stayed within an acceptable range. The typical In Fig. 30, TGA 

revealed thermal degradation at 10 weight % was at 559 for the 10K-PECH amine which is 

higher than the MOB polymerized 7.5KPECH at Td10% at 351°C. Thermal degradation at 10 

weight % was at 538 for the 30KPECH amine. These values are also higher than the MOB 

polymerized 30KPECH at Td10% at 370. These analyses reveal that grafting the NPs with this 

polymer maintains the relatively low Tg while improving thermal resistance.  

44 

 
 
Figure 30: TGA curves of 7.5KPECH (black) and 30KPECH (gray) polymerized by MOB, 
GNPNH10kPECH (red), GNPNH30KPECH (blue) 

Ionic Conductivity Study 

Figure 31 shows the room temperature ionic conductivity of the samples. To analyze the lithium 

conductivity for this composite electrolyte, LiTFSI was added to the matrix for lithium source. 

The composite samples have shown to outperform the neat 7.5KPECH sample with lithium salt 

addition. The 2.5 wt % revealed a conductivity at 3.6 x10-3 mS/cm. The 2.5 wt% sample did not 

significantly increase conductivity from the neat 7.5KPECH sample. This resulted in doubling 

the amount of GNPNHPECH in the system at 5 wt% for analysis. The GNPNH10KPECH 

sample resulted in the highest conductivity at 4.81 x10-3 mS/cm which can also be attributed to 

the increased amount of free volume when compared to the GNPNH30KPECH (4.0 x10-3 

mS/cm). Further work needs to be investigated to understand the ceramic-polymer-ion 

interaction that seems to also increase conductivity. Like the work in the preceding chapter, 

lithium transference needs to be investigated as well.40 

45 

 
 
Figure 31: Ionic Conductivity of GNPNHPECH of different GNP wt% 

Conclusion 

Composites are an obvious option when expanding into lithium battery electrolyte applications 

as they combine the ion permeable properties of a polymer and strengthening attributes of a filler 

to create a robust and efficient electrolyte. This project utilized silica nanoparticles to 

successfully graft initiators that have shown epoxide polymerization capabilities to the surface. 

NMR was used to confirm GNP-initiator synthesis. While the glass transition temperature of the 

GNPNHPECH samples were comparable to 7.5KPECH and 30KPECH, the samples were shown 

to be more resistive to thermal degradation. The knowledge from this and the previous project 

will be used to advance composite synthesis by contributing to the structure-property relationship 

understanding. The electrochemical properties have shown improvement with just the addition of 

the GNPNHPECH into the matrix. Overall, this work has contributed to the understanding of the 

compatibility of ether matrix and ether-based composite fillers. 

46 

 
Future Work 

There are quite a few ways to extend this project. Since incorporating the GNP only shows 

positive results for most properties, it is important to explore higher GNP wt% to increase 

electrochemical performance. We will also analyze the electrochemical window and lithium 

mobility. The next step is to build an ether composite with a single ion conductor ether matrix. 

The GNPNHPECH could combat any negative changes to the thermophysical properties and 

improve lithium transference and ionic conductivity. We will also explore different initiators and 

different functionalized nanoparticles to synthesize ether-based composites. 

47 

 
 
 
EXPLORING AMINE-BASED INITIATORS FOR EPOXIDE 
POLYMERIZATION 

ABSTRACT 

Polyethers are one of the leading polymeric materials for many applications. To promote and 

expand widespread polyether application, it is pertinent to find new ways of producing them 

efficiently.  While traditional methods have proven to be useful, there are only a few ways to 

efficiently polymerize functional epoxides. Amines have been used for initiator and/or catalysts 

for polymerization systems for years. The previous composite work utilized an amine-based 

initiator to modify the surface of silica nanoparticles that allowed for epoxide polymerization. In 

this research we consider different amines to expand epoxide polymerization methods for 

composite application and general use.  Using the basis of mono(μ-alkoxo)bis(alkylaluminum) 

(MOB) work, the research presented focuses on trying to synthesize one-pot polymerization 

platforms. This project presents facile systems that produce polyether homopolymers using 

epichlorohydrin (ECH), butylene oxide (BO), and propylene oxide (PO). This platform utilizes 

compounds with secondary and primary amines to create a metal complex capable of living 

polymerization. Proton (1H) and carbon (12C) NMR were used to analyze chemical 

composition. It is intended to investigate the kinetics of these initiators with various functional 

polyethers to advance polyether composite applications. 

48 

 
 
 
 
 
 
Introduction 

Ethylene oxide (EO) was the first epoxide to be polymerized 1863.14  Vandenberg’s catalyst is 

one of the most known techniques, but it is difficult to control for high molecular weights with 

narrow polydispersities targets.16,17 AROP and cationic ROP techniques are common, but are 

difficult to use when trying to produce functional polyethers and low molecular weights.15 These 

methods were effective, unless trying to polymerize functional epoxides. Mono(μ-

alkoxo)bis(alkylaluminum) (MOB), discovered in 2017, was the first platform that could 

efficiently polymerize functional epoxides in a controlled manner.18,19 This system can 

polymerize various epoxides with different functionalities, such as chloromethyl, alkenes, and 

alkynes groups. This method is extremely fast compared to traditional methods, polymerizes 

>98% of the epoxide, and it minimizes or removes the necessity of solvents for the reaction.  

With inspiration from MOB precursor platform and the grafted nanoparticle from the second 

project, this work will explore using similar synthetic methods to create easy epoxide 

polymerization systems. As we have successfully grafted nanoparticles with amine-based 

initiators, it is pertinent to explore other compounds that will allow for the same functionality for 

epoxide polymerization. Work has been published using thiol initiators to efficiently polymerize 

epoxides with varying structures and narrow polydispersity.55 This work will reveal different 

amine initiators that have similar functionality for epoxides. Amines are primary reactants in 

polymerizations for many polymers and have been for decades.23,24  Some amines are prone to 

react with metal complexes in a variety of compounds where they could act as catalysts, 

initiators, or both for ROPs.25 

This project is preliminary work that explores amine initiators for epoxide polymerizations that 

can be expanded upon to increase polyether application in composite and electrolyte synthesis. 

49 

 
We utilize three separate amine compounds (N-ethylethylenediamine, benzylamine, and 3-

aminopropanol) to polymerize epichlorohydrin, butylene oxide, and propylene oxide. The work 

will contribute to expanding polymer electrolyte knowledge by extending initiator usage that 

could affect polymerization method, composite composition, and structure.  

Experimental Section 

Materials: 

Hexamethylenediamine (Sigma-Aldrich), N-ethylethylenediamine (Sigma-Aldrich), benzylamine 

(Sigma-Aldrich), 3-aminopropanol (Sigma-Aldrich), trimethylaluminum (TMA) (2.0 M in 

hexanes, Sigma-Aldrich), triethylamine (TEA) (Sigma-Aldrich) and anhydrous hexanes (Sigma-

Aldrich >99%) were all used for preparing catalyst and initiators for polymerization of 

epichlorohydrin (ECH) (Sigma-Aldrich) and butylene oxide (BO) in glovebox without any 

modification. Glovebox was used to carry out all moisture and oxygen sensitive reactions in 

nitrogen environment. 

Methanol (MeOH, Fisher, Certified ACS), hexanes (Fisher, Certified ACS) and dichloromethane 

(DCM) (Fisher, Certified ACS) were used to remove unreacted monomers and catalysts from 

polymer products. 

Chloroform-d (Cambridge Isotope Laboratories, Inc. 99.8%) and dimethyl sulfoxide-d6 

(Cambridge Isotope Laboratories, Inc. 99.8%) were used for preparing NMR samples without 

any alteration. 

Instrumentation: 

All (1H, 13C, HSQC, GCOSY) NMR spectroscopy was performed on Agilent DDR2 500 MHz 

NMR spectrometer using deuterated solvents at room temperature. The chemical shifts are 

50 

 
reported in parts per million (ppm) and are referenced using the residual peak from the 

deuterated solvent. 

Methods: 

Synthesis of trimethylaluminum and triethylamine adduct (NAl Catalyst)  

A reaction vial was charged with a stir bar and 6.35 mL of 2.0 M trimethylaluminum in hexane 

(6.35 mL, 12.7 mmol) was added and cooled to –78ºC in a dry nitrogen glovebox. To this vial, 1 

mL triethylamine (12.7 mmol) was added slowly. The solution was set to stir and warm to room 

temperature overnight. These crystals were then washed with anhydrous hexanes three times to 

remove excess reactant and dried under vacuum.  

1H NMR (CDCl3, 500 MHz) δ 0.14 to -0.15 (m, –Al[–CH̲ 2–CH–(CH3)2]2, and m, –Al[–CH̲ 2–
CH–(CH3)2]3), 0.92 (m, –Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 1.82 (m, 
–Al[–CH2–CH–(CH3)2]2, and m, –Al[–CH2–CH–(CH3)2]3), 2.59 (s, N–(CH̲ 3)2), 2.87 (t, N–
CH2–CH2–O), 3.97 (t, N–CH2–CH̲ 2–O)  

Scheme 10: Synthesis of NAl Adduct 

Figure 32: 1H and 13C NMR of NAl adduct 

51 

 
 
 
Synthesis of Amine initiators 

The appropriate amount of TMA solution  (dependent  on the amine compound) was added to  a 

reaction vial with a magnetic stirrer and cooled to -50 – -70ºC inside a glovebox under nitrogen 

atmosphere. To this vial, 1mL of the amine compounds was added dropwise. The reaction was 

carried out by continuous stirring until it warms to room temperature overnight. These crystals 

were then washed with anhydrous hexanes three times to remove excess reactant and dried under 

vacuum.55 

 Reaction Scheme 10: Synthesis of Amine Initiators 

General procedure for polymerization using amine initiators  

All polymerizations were performed in a septum-capped 20 mL reaction vial under inert 

atmosphere in glovebox. The vials were charged with a stir bar, 5 g of the monomer(s) and 50 

mg of NAl adduct catalyst, and 50 mg of initiator. The reactions had to be heated to a reaction 

temperature of 60°C. All polymerizations were carried out for 5 hours-3 days (until its >90% 

polymerized). Reactions were quenched with methanol and dissolved in DCM to remove 

aluminum. The resulting solution was added dropwise into MEOH to precipitate out the desired 

polymer product. The polymer was first dried using rotary evaporator and then kept under 

vacuum overnight to remove residual solvent. 

PECH: 1H NMR (CDCl3, 500 MHz) δ 2.97–3.53 (m, (–O–CH̲ 2–CH̲ (CH̲ 2–Cl)–O–) 
13C NMR (CDCl3, 125 MHz) δ 43.71 (m, (–O–CH2–CH(CH̲ 2–Cl)–O–), 69.5(m, (–O–CH̲ 2–
CH(CH2–Cl)–O–), 79.02 (m, (–O–CH2–CH̲ (CH2–Cl)–O–) 

52 

 
PBO: 1H NMR (CDCl3, 500 MHz) δ 3.12–3.63 (m, (–O–CH̲ 2–CH̲ (CH2 - CH3)–O–), δ 1.91(m, 
(–O–CH2–CH(CH2 - CH̲ 3)–O–), δ 1.41–1.62 (m, (–O–CH2–CH(CH̲ 2 - CH3)–O–), 
13C NMR (CDCl3, 125 MHz) δ 80.69 (m, (–O–CH2–CH̲ (CH2 - CH3)–O–), δ 72.34 (m, (–O–
CH̲ 2–CH(CH2 - CH3)–O–)δ 9.76 (m, (–O–CH2–CH(CH2 - CH̲ 3)–O–), δ 24.73 (m, (–O–CH2–
CH(CH̲ 2 - CH3)–O–) 

PPO: 1H NMR (CDCl3, 500 MHz) δ 3.38–3.59 (m, (–O–CH̲ 2–CH̲ (CH3)–O–), δ 1.12 (m, (–O–
CH2–CH(CH̲ 3)–O–) 
13C NMR (CDCl3, 125 MHz) δ 75.32 (m, (–O–CH2–CH̲ (CH3)–O–), δ 73.36 (m, (–O–CH̲ 2–
CH(CH3)–O–), δ 17.36 (m, (–O–CH2–CH(CH̲ 3)–O–) 

Scheme 11: Epoxide Polymerization with amine initiators 

Results 

Chemical Characterization:  

NMR 

Figure 32: 1H and 13C NMR of BA-TMA 

All the initiator samples were dissolved in CDCl3 for NMR analysis.  For the BA-TMA, the 

benzyl protons reside at δ 7.42 – 7.28. The methylene protons are at δ 3.88, and the methyl 

53 

 
 
 
protons are at δ -0.86. The amine proton is at δ 2.56. For the 13C NMR, the quaternary carbon is 

found at δ 139.5 and the residual benzyl carbons reside at δ 130 – 127. The methylene carbon is 

at δ 45.65, and the methyl carbons are at δ -9.32.  

Figure 33: 1H and 13C NMR of 3AP-TMA 

For the 3AP-TMA, the methylene protons reside at δ 3.76, δ 2.93, and δ 165. The methyl protons 

are at δ -1.05. The amine proton is at δ 3.32. For the 13C NMR, the methylene protons reside at δ 

62.74, δ 40.27, and δ 30.32. The methyl protons are at δ -1.05.   

54 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 34: 1H and 13C NMR of EEDA-TMA 

For the EEDA-TMA, the methylene protons are at δ 2.77-2.62, and the methyl protons are at 

δ1.11 and δ -0.72. The amine proton is not appearing and due to reactivity of aluminum with 

water, a D2O exchange was not possible. For the 13C NMR, the methylene protons are at δ 

48.53, δ 48.27, and δ 39.72. The methyl protons are at δ15.25 and δ -9.38.  

These initiators have polymerized 3 epoxides, ECH, PO and BO. We can speculate that the 

initiator coordinates with the monomer similar to the mechanism of the Vandenberg catalyst. The 

N-Al adduct seems to activate the monomer for ring opening similar to monomer activated ring 

opening polymerization (MAROP) mechanism.55 

Conclusion 

Epoxides are favorable starting material for many applications, but there are few ways to 

efficiently produce them with varying composition (structure, molecular weight, functionality, 

etc.); in turn minimizing their use. This work investigated utilizing amine compounds 

(benzylamine, ethylethylene diamine, and aminopropanol) to advance epoxide polymerization 

55 

 
methods. We revealed a simple synthesis for initiators for epoxide polymerization (ECH, BO, 

PO). While there is still quite a bit of work to do for this study, the work reveals that each 

complex, combination of each amine compound and trimethyl aluminum, has the capability to 

polymerize different epoxides. The initiator chemical composition and epoxide polymerization 

was verified by NMR characterization.  

Future Work 

The next steps of this work are to investigate the mechanism and kinetics of the polymerization 

reaction, widen epoxide options, and incorporate the initiators into ether composite synthesis. 

investigate grafting these initiators to the surface of nanoparticles. By understanding the 

mechanism and kinetics of each platform, we will learn which functional epoxides can 

successfully be polymerized and possibly the timeframe the reaction takes to complete. This in 

turn, along with experimental trial and error can reveal which epoxides with functional groups 

can be utilized with the different initiators. The initiators with additional reactive sites like amine 

protons can be used to explore composite synthesis by chemical bonding these sites to 

nanoparticles and other fillers that can affect electrochemical and thermophysical properties. 

56 

 
 
 
CONCLUSION 

The first chapter introduces polyethers and magnifies their applications and uses. We have noted 

the recent innovations with epoxide polymerizations and how newer polymerization platforms 

push the green chemistry initiative with production methods. We also discussed their importance 

and possible longevity in the electrolyte field for LIBs/LMBs by addressing concerns. We 

attempt to expand the knowledge and application of polyethers for these applications by 

synthesizing ether based SIC electrolytes (second chapter), ether composites (third chapter), and 

new amine initators to synthesize ethers (fourth chapter). 

The second chapter of this work exemplified the use of polyethers as a matrix for single-ion 

conductors as electrolytes for LMBs. Polyethers in high and low molecular weight were 

polymerized using MOB system. Those polymers were then tuned by adding an amine anion that 

underwent cation exchange to be a lithium-ion carrier. The results showed that it is possible to 

use varying molecular weight polyethers after a relatively simple modification can be used as a 

functioning electrolyte. The polymer offers a relatively robust and temperature-stable matrix. 

Glass transition temperature remained essentially constant and in an operable temperature range 

throughout synthesis. SICs, having the anion tethered to the polymer backbone, allows for 

controlled Li+ loading and removes the anion polarization and polymer chain motion 

impediment, and ion aggregation.  

The third chapter introduced the synthesis of ether composites silica nanoparticles. Initiators 

were grafted onto the surface of the nanoparticles and NMR was used to confirm GNP-initiator 

synthesis. The glass transition temperature of the GNPNHPECH samples were similar to 

polymers polymerized with MOB platform, 7.5KPECH and 30KPECH, and the samples were 

57 

 
 
shown to be more resistive to thermal degradation. The ionic conductivity have shown 

improvement with just the addition of the GNPNHPECH into the matrix.  

The fourth chapter reveals the preliminary work done on researching amine-based initiator for 

epoxide polymerizations. Benzylamine, ethylethylene diamine, and aminopropanol were used to 

create a metal complex capable of polymerizing certain epoxides. These initiators were easy to 

synthesize and capable of one-pot polymerization as the system only requires: the initiator, 

monomer, and NAl adduct catalyst.  As of now, three epoxides were successfully polymerized 

(ECH, BO, PO). The initiator chemical composition and epoxide polymerization was verified by 

NMR characterization.  

The research presented in this work revealed alternative ways to promote the unique use of 

polyether for LIB/LMB electrolyte applications. Expanding from SIC synthesis, composite 

synthesis, and epoxides platforms introduced new composition possibilities as the composition-

property relationships were revealed, showing improvement in analyzed areas (thermal transition 

and ionic conductivity). This work focused on producing and utilizing polyether while aligning 

with the green chemistry principles to promote sustainability and innovation for the advancement 

of LMBs.  

58 

 
 
 
 
 
 
FUTURE WORK 

The first steps for the SIC work includes exploring electrochemical window, investigating 

lithium transference, and expanding molecular weight variation. The electrochemical window 

(ECW) will reveal limiting operating voltage range for these electrolytes as it entails the 

potential range where the electrolyte does not participate in redox reactions. We can understand 

the affect composition has on ECW, and subsequently electrolyte stability. We will also 

investigate Li+ transference to quantify the amount of lithium moving throughout the electrolyte 

as well as correlate lithium mobility to the electrolyte composition. The results revealed a lower 

molecular weight influenced higher ionic conductivity, but higher molecular weight matrices 

result in a more robust polymer. Expanding on the composition study, the molecular weight 

needs to be adjusted to find the optimal molecular weight.  

There are quite a few ways to extend the composite-nanoparticle work. Since incorporating the 

GNP only shows positive results for most properties, it is important to explore higher GNP wt% 

to increase electrochemical performance. We will also analyze the electrochemical window and 

lithium mobility. The next step is to build an ether composite with a single ion conductor ether 

matrix. The GNPNHPECH could combat any negative changes to the thermophysical properties 

and improve lithium transference and ionic conductivity. We will also explore different initiators 

and different functionalized nanoparticles to synthesize ether-based composites. 

The next steps of the amine initiator research are to investigate the mechanism and kinetics of the 

polymerization reaction, widen epoxide options, and incorporate the initiators into ether 

composite synthesis. investigate grafting these initiators to the surface of nanoparticles. By 

understanding the mechanism and kinetics of each platform, we will learn which functional 

epoxides can successfully be polymerized and possibly the timeframe the reaction takes to 

59 

 
 
complete. This in turn, along with experimental trial and error can reveal which epoxides with 

functional groups can be utilized with the different initiators. The initiators with additional 

reactive sites like amine protons can be used to explore composite synthesis by chemical bonding 

these sites to nanoparticles and other fillers that can affect electrochemical and thermophysical 

properties. 

60 

 
 
 
REFERENCES 

1. 

2. 

3. 

Nuyken, O. & Pask, S. D. Ring-opening polymerization-An introductory review. Polymers 
(Basel) 5, 361–403 (2013). 

Engels, H. W. et al. Polyurethanes: Versatile materials and sustainable problem solvers for 
today’s challenges. Angewandte Chemie - International Edition vol. 52 9422–9441 
Preprint at https://doi.org/10.1002/anie.201302766 (2013). 

Verkoyen, P. & Frey, H. Amino-functional polyethers: Versatile, stimuli-responsive 
polymers. Polymer Chemistry vol. 11 3940–3950 Preprint at 
https://doi.org/10.1039/d0py00466a (2020). 

4.  Mindemark, J., Lacey, M. J., Bowden, T. & Brandell, D. Beyond PEO—Alternative host 

materials for Li+-conducting solid polymer electrolytes. Progress in Polymer Science vol. 
81 114–143 Preprint at https://doi.org/10.1016/j.progpolymsci.2017.12.004 (2018). 

5. 

6. 

7. 

8. 

9. 

George, J. & Kumar, V. V. Designing a novel poly (methyl vinyl ether maleic anhydride) 
based polymeric membrane with enhanced antifouling performance for removal of 
pentachlorophenol from aqueous solution. Environ Res 223, (2023). 

Iversen, L. J. L. et al. The Emergence of Edible and Food-Application Coatings for Food 
Packaging: A Review. Molecules vol. 27 Preprint at 
https://doi.org/10.3390/molecules27175604 (2022). 

Jiang, J. et al. Synthesis of novel poly (aryl ether sulfone) containing amino groups for gas 
separation membrane. Materials Letters 349, 134729 (2023). 

Kumar, S., Sharma, N., Kaur, S. & Singh, P. Pseudo-crown ether III: Naphthalimide-Pd(II) 
based fluorogenic ensemble for solution, vapour and intracellular detection of amine and 
anti-counterfeiting applications. J Photochem Photobiol A Chem 430, (2022). 

Herzberger, J. et al. Polymerization of ethylene oxide, propylene oxide, and other alkylene 
oxides: Synthesis, novel polymer architectures, and bioconjugation. Chemical Reviews 
vol. 116 2170–2243 Preprint at https://doi.org/10.1021/acs.chemrev.5b00441 (2016). 

10. 

Staudinger, H. & Lohmann, H. Über hochpolymere Verbindungen. 81. Mitteilung. Über 
eukolloides Polyäthylenoxyd. Justus Liebigs Ann Chem 505, 41–51 (1933). 

11.  Chen, S., Li, L., Zhao, C. & Zheng, J. Surface hydration: Principles and applications 
toward low-fouling/nonfouling biomaterials. Polymer vol. 51 5283–5293 Preprint at 
https://doi.org/10.1016/j.polymer.2010.08.022 (2010). 

12.  Klein, R. & Wurm, F. R. Aliphatic polyethers: Classical polymers for the 21st century. 

Macromolecular Rapid Communications vol. 36 1147–1165 Preprint at 
https://doi.org/10.1002/marc.201500013 (2015). 

61 

 
13. 

Penczek, S., Cypryk, M., Duda, A., Kubisa, P. & Słomkowski, S. Living ring-opening 
polymerizations of heterocyclic monomers. Progress in Polymer Science (Oxford) vol. 32 
247–282 Preprint at https://doi.org/10.1016/j.progpolymsci.2007.01.002 (2007). 

14.  Herzberger, J. et al. Polymerization of ethylene oxide, propylene oxide, and other alkylene 

oxides: Synthesis, novel polymer architectures, and bioconjugation. Chemical Reviews 
vol. 116 2170–2243 Preprint at https://doi.org/10.1021/acs.chemrev.5b00441 (2016). 

15.  Andrea, K. A., Plommer, H. & Kerton, F. M. Ring-opening polymerizations and 

copolymerizations of epoxides using aluminum- and boron-centered catalysts. European 
Polymer Journal vol. 120 Preprint at https://doi.org/10.1016/j.eurpolymj.2019.08.029 
(2019). 

16.  Vandenberg, E. J. Organometallic catalysts for polymerizing monosubstituted epoxides. 

Journal of Polymer Science 47, 486–489 (1960). 

17.  Vandenberg, E. J. High polymers from symmetrical disubstituted epoxides. Journal of 

Polymer Science 47, 489–491 (1960). 

18. 

19. 

Ferrier, R. C. et al. Four-fold increase in epoxide polymerization rate with change of 
alkyl-substitution on mono-μ-oxo-dialuminum initiators. Polym Chem 8, 4503–4511 
(2017). 

Imbrogno, J., Ferrier, R. C., Wheatle, B. K., Rose, M. J. & Lynd, N. A. Decoupling 
Catalysis and Chain-Growth Functions of Mono(μ-alkoxo)bis(alkylaluminums) in 
Epoxide Polymerization: Emergence of the N-Al Adduct Catalyst. ACS Catal 8, 8796–
8803 (2018). 

20.  Cui, S., Borgemenke, J., Liu, Z., Keener, H. M. & Li, Y. Innovative sustainable conversion 
from CO2 and biodiesel-based crude glycerol waste to bio-based polycarbonates. Journal 
of CO2 Utilization 34, 198–206 (2019). 

21.  Kreye, O., Mutlu, H. & Meier, M. A. R. Sustainable routes to polyurethane precursors. 

Green Chemistry vol. 15 1431–1455 Preprint at https://doi.org/10.1039/c3gc40440d 
(2013). 

22.  Bell, B. M. et al. Glycerin as a renewable feedstock for epichlorohydrin production. The 

GTE process. Clean (Weinh) 36, 657–661 (2008). 

23. 

Schwindeman, J. A., Eric, L. ;, Granger, J., Charlotte, N. C. & Paul, R. AMINE ANONIC 
POLYMERIZATION INITIATORS AND FUNCTIONALIZED POLYMERS DERVED 
THEREFROM. (2000). 

24.  Kim, K. et al. Rational Design of Efficient Amine Reductant Initiators for Amine-
Peroxide Redox Polymerization. J Am Chem Soc 141, 6279–6291 (2019). 

25.  Ryzhakov, D. et al. Organo-catalyzed/initiated ring opening co-polymerization of cyclic 

anhydrides and epoxides: An emerging story. Polymer Chemistry vol. 12 2932–2946 
Preprint at https://doi.org/10.1039/d1py00020a (2021). 

62 

 
26.  Whittingham, M. S. Electrical Energy Storage and Intercalation Chemistry. Science (1979) 

192, 1126–1127 (1976). 

27.  Goodenough, J. B. Evolution of strategies for modern rechargeable batteries. Acc Chem 

Res 46, 1053–1061 (2013). 

28.  Ertl, G. The nobel prize in chemistry. Nobel Lectures: Chemistry: 2006 - 2010 37–38 

(2014) doi:10.1142/9789814635660_0002. 

29.  He, L. P., Sun, S. Y., Song, X. F. & Yu, J. G. Recovery of cathode materials and Al from 

spent lithium-ion batteries by ultrasonic cleaning. Waste Management 46, 523–528 (2015). 

30.  Lyu, P. et al. Recent advances of thermal safety of lithium ion battery for energy storage. 

Energy Storage Materials vol. 31 195–220 Preprint at 
https://doi.org/10.1016/j.ensm.2020.06.042 (2020). 

31. 

Fenton, D. E., Parker, M. & Wright, P. V. Complexes of Alkali Metal Ions with 
Poly(Ethylene Oxide). Polymer (Guildf) 14, 589 (1973). 

32.  Xue, Z., He, D. & Xie, X. Poly(ethylene oxide)-based electrolytes for lithium-ion 

batteries. J Mater Chem A Mater 3, 19218–19253 (2015). 

33.  Hallinan, D. T. & Balsara, N. P. Polymer electrolytes. Annual Review of Materials 

Research vol. 43 503–525 Preprint at https://doi.org/10.1146/annurev-matsci-071312-
121705 (2013). 

34.  Long, L., Wang, S., Xiao, M. & Meng, Y. Polymer electrolytes for lithium polymer 
batteries. Journal of Materials Chemistry A vol. 4 10038–10039 Preprint at 
https://doi.org/10.1039/c6ta02621d (2016). 

35.  Vadhva, P. et al. Electrochemical Impedance Spectroscopy for All-Solid-State Batteries: 

Theory, Methods and Future Outlook. ChemElectroChem vol. 8 1930–1947 Preprint at 
https://doi.org/10.1002/celc.202100108 (2021). 

36.  Bocharova, V. et al. Influence of Chain Rigidity and Dielectric Constant on the Glass 

Transition Temperature in Polymerized Ionic Liquids. Journal of Physical Chemistry B 
121, 11511–11519 (2017). 

37.  Yamamoto, H. & Matsui, M. Lithium Salt and Method For Producing Thereof. vol. 2 

(2011). 

38.  Novikov, V. N. & Rössler, E. A. Correlation between glass transition temperature and 

molecular mass in non-polymeric and polymer glass formers. Polymer (Guildf) 54, 6987–
6991 (2013). 

39. 

Shukla, G. & Ferrier, R. C. The versatile, functional polyether, polyepichlorohydrin: 
History, synthesis, and applications. Journal of Polymer Science vol. 59 2704–2718 
Preprint at https://doi.org/10.1002/pol.20210514 (2021). 

63 

 
40.  Giffin, G. A. The role of concentration in electrolyte solutions for non-aqueous lithium-

based batteries. Nature Communications vol. 13 Preprint at 
https://doi.org/10.1038/s41467-022-32794-z (2022). 

41.  Hsissou, R. et al. Polymer composite materials: A comprehensive review. Composite 

Structures vol. 262 Preprint at https://doi.org/10.1016/j.compstruct.2021.113640 (2021). 

42.  Le Guen, M. J., Newman, R. H., Fernyhough, A., Emms, G. W. & Staiger, M. P. The 

damping-modulus relationship in flax-carbon fibre hybrid composites. Compos B Eng 89, 
27–33 (2016). 

43.  Zhou, W. et al. Polymer composites filled with core@double-shell structured fillers: 

Effects of multiple shells on dielectric and thermal properties. Compos Sci Technol 181, 
(2019). 

44.  Chen, J. & Gao, X. Thermal and electrical anisotropy of polymer matrix composite 

materials reinforced with graphene nanoplatelets and aluminum-based particles. Diam 
Relat Mater 100, (2019). 

45.  De, S. et al. Interface modification of carbon fiber reinforced epoxy composite by 

hydroxyl/carboxyl functionalized carbon nanotube. in Materials Today: Proceedings vol. 
27 1473–1478 (Elsevier Ltd, 2020). 

46. 

dua, S. et al. Potential of natural fiber based polymeric composites for cleaner automotive 
component production -a comprehensive review. Journal of Materials Research and 
Technology 25, 1086–1104 (2023). 

47.  Asyraf, M. R. M. et al. Synthetic nanofillers in polymer composites for aerospace 

industry. in Synthetic and Natural Nanofillers in Polymer Composites 291–311 (Elsevier, 
2023). doi:10.1016/b978-0-443-19053-7.00018-4. 

48.  Zulaikha, W., Zaki Hassan, M. & Abdul Aziz, S. Nanoparticle-embedded hydrogels as a 

functional polymeric composite for biomedical applications. Mater Today Proc (2023) 
doi:10.1016/j.matpr.2023.05.668. 

49.  Zhang, M. et al. Recent advances in polymers and polymer composites for food 

packaging. Materials Today vol. 53 134–161 Preprint at 
https://doi.org/10.1016/j.mattod.2022.01.022 (2022). 

50.  Ngai, K. S., Ramesh, S., Ramesh, K. & Juan, J. C. A review of polymer electrolytes: 
fundamental, approaches and applications. Ionics (Kiel) 22, 1259–1279 (2016). 

51.  Liu, S. et al. Effect of nano-silica filler in polymer electrolyte on Li dendrite formation in 

Li/poly(ethylene oxide)-Li(CF3SO2)2N/Li. J Power Sources 195, 6847–6853 (2010). 

52.  Ai, S., Mazumdar, S., Li, H., Cao, Y. & Li, T. Nano-silica doped composite polymer 

chitosan/poly(ethylene oxide)-based electrolyte with high electrochemical stability 
suitable for quasi solid-state lithium metal batteries. Journal of Electroanalytical 
Chemistry 895, (2021). 

64 

 
53.  Kurc, B. Composite gel polymer electrolyte with modified silica for LiMn2O4 positive 

electrode in lithium-ion battery. Electrochim Acta 190, 780–789 (2016). 

54.  El Harrak, A., Carrot, G., Oberdisse, J., Eychenne-Baron, C. & Boué, F. Surface-atom 

transfer radical polymerization from silica nanoparticles with controlled colloidal stability. 
Macromolecules 37, 6376–6384 (2004). 

55. 

Safaie, N. et al. Facile synthesis of epoxide-co-propylene sulphide polymers with 
compositional and architectural control. Polym Chem (2022) doi:10.1039/d2py00005a. 

65 

 
  
 
 
ECH:PPO Unit Calculation for Statistical Copolymer 

APPENDIX 

Using 1H NMR, neat polymers were run with CDCl3 that has a residual solvent peak of δ 7.26. 

The methyl group from PPO found at δ XX had an integration set to 3 and the corresponding 

integration from the polymer backbone (PECH/PPO) peaks at δ 3.85-3.4 was noted and plugged 

into the following equation.  

# 𝑜𝑓 𝐸𝐶𝐻 𝑈𝑛𝑖𝑡𝑠 =

(𝑃𝑜𝑙𝑦𝑚𝑒𝑟 𝐵𝑎𝑐𝑘𝑏𝑜𝑛𝑒 𝑃𝑟𝑜𝑡𝑜𝑛 𝐼𝑛𝑡𝑒𝑔𝑟𝑎𝑡𝑖𝑜𝑛 − 3)
5

Figure 35: 1H NMR of 30KPECH polymerized by MOB 

66 

 
 
 
 
Figure 36: Integrated  1H NMR of 75PECH polymerized by MOB 

67 

 
 
 
 
 
 
 
 
 
 
 
Figure 37: 1H NMR of 55PECH and 55PECH-SIC   

68 

 
 
 
  
Figure 38: Integrated 1H NMR of 55PECH polymerized by MOB 

Figure 39: 19F NMR of 55PECH-SIC 

69 

 
 
 
 
 
Figure 40: 6Li NMR of 55PECH-SIC 

Figure 41: 1H NMR of 7.5KPECH and 7.5KPECH-SIC   

70 

 
 
 
 
Figure 42: 13C NMR of 7.5KPECH and 7.5KPECH-SIC  

Figure 43: 19F NMR of 7.5KPECH-SIC 

71 

 
   
 
Figure 44: 6Li NMR of 7.5KPECH-SIC  

Table 1: Glass Transition Temperatures of Neat Ether, Ether-SIC, and Ether-SIC Li+  

72 

 
 
 
 
 
 
 
 
Figure 45: DSC Curve of (1) 30KPECH and (2) 7.5KPECH  

Figure 46: DSC Curve of (1) 75PECH and (2) 55PECH 

Figure 47: FTIR Spectra 30KPECH 

73 

 
  
 
 
 
Figure 48: FTIR Spectra 75PECH 

Figure 49: FTIR Spectra 55PECH 

74 

 
  
 
 
 
 
 
Figure 50: FTIR Spectra 7.5KPECH 

Table 2: Ionic Conductivity of Neat Ether, Ether-SIC, and Ether-SIC LI+ 

75 

 
 
 
 
Figure 51: Nyquist plot of 30KPECH-SIC Li+ with LiTFSI ([EO]/[Li]= 10) 

Figure 52: Nyquist plot of 75PECH-SIC with LiTFSI ([EO]/[Li]= 10) 

76 

 
 
 
 
 
 
 
 
 
 
 
 
Figure 53: Nyquist plot of 75PECH-SIC Li+ with LiTFSI ([EO]/[Li]= 10) 

Figure 54: Nyquist plot of 55PECH with LiTFSI ([EO]/[Li]= 10) 

77 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 55: Nyquist plot of 55PECH-SIC Li+ 

Figure 56: Nyquist plot of 55PECH-SIC with LiTFSI ([EO]/[Li]= 10) 

78 

 
 
Figure 57: Nyquist plot of 55PECH-SIC Li+ with LiTFSI ([EO]/[Li]= 10) 

Figure 58: Nyquist plot of 7.5KPECH 

79 

 
 
 
 
 
 Figure 59: Nyquist plot of 7.5KPECH-SIC Li+ 

Figure 60: Nyquist plot of 7.5KPECH with LiTFSI ([EO]/[Li]= 10) 

80 

 
 
Figure 61: Nyquist plot of 7.5KPECH-SIC with LiTFSI ([EO]/[Li]= 10) 

Figure 62: Nyquist plot of 7.5KPECH-SIC Li+ with LiTFSI ([EO]/[Li]= 10) 

81 

 
 
 
Figure 63: 1H NMR of GNPNH30KPECH 

Figure 64: 13C NMR of GNPNH30KPECH 

82 

 
 
Figure 65: 1H NMR of GNPNH10KPECH 

83 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 66: 13C NMR of GNPNH30KPECH 

Table 3: Ionic Conductivity of Ether Composites  

84 

 
 
 
 
 
 
 
 
 
 
 
Figure 67: Nyquist plot of Ether Composite Using 2 wt% of GNPNH30KPECH with LiTFSI 
([EO]/[Li]= 10) 

Figure 68: Nyquist plot of Ether Composite Using 5 wt% of GNPNH10KPECH with LiTFSI 
([EO]/[Li]= 10) 

85 

 
 
 
 
 
 
 
 
 
 
Figure 69: Nyquist plot of Ether Composite Using 5 wt% of GNPNH30KPECH with LiTFSI 
([EO]/[Li]= 10) 

Figure 70: Integrated 1H NMR of 3AP-TMA 

86 

 
 
 
Figure 71: HSQC of NMR of 3AP-TMA 

87 

 
 
 
 
 
 
 
 
 
 
 
 
Figure 72: GCOSY of NMR of 3AP-TMA 

Figure 73: 1H NMR of PECH polymerized by 3AP-TMA 

88 

 
 
 Figure 74: 1H NMR of PECH polymerized by 3AP-TMA 

Figure 75: 1H NMR of PBO polymerized by 3AP-TMA 

89 

 
  
 
 
Figure 76: 13C NMR of PBO polymerized by 3AP-TMA 

90 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 77: 1H NMR of PPO polymerized by 3AP-TMA 

Figure 78: 13C NMR of PPO polymerized by 3AP-TMA 

91 

 
 
Figure 79: Integrated 1H NMR of BA-TMA 

92 

 
 
 
 
 
 
 
 
 
 
 
 
Figure 80: HSQC NMR of BA-TMA 

Figure 81: 1H NMR of PECH polymerized by BA-TMA 

93 

 
Figure 82: 13C NMR of PECH polymerized by BA-TMA 

94 

 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 83: 1H NMR of PBO polymerized by BA-TMA 

Figure 84: 13C NMR of PBO polymerized by BA-TMA 

95 

 
 
 
 
 
 
Figure 85: 1H NMR of PPO polymerized by BA-TMA 

96 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 86: 13C NMR of PPO polymerized by BA-TMA 

Figure 87: 1H NMR of EEDA-TMA 

97 

 
 
 
Figure 88: HSQC NMR of EEDA-TMA 

98 

 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 89: GCOSY NMR of EEDA-TMA 

Figure 90: 1H NMR of PECH polymerized by EEDA-TMA (sample has residual ECH) 

99 

 
 
 
Figure 91: 13C NMR of PECH polymerized by EEDA-TMA 

100 

 
 
 
Figure 92: 1H NMR of PBO polymerized by EEDA-TMA 

Figure 93: 13C NMR of PBO polymerized by EEDA-TMA 

101 

 
 
 
 
Figure 94: 1H NMR of PPO polymerized by EEDA-TMA 

Figure 95: 13C NMR of PPO polymerized by EEDA-TMA 

102