HIII‘IHIIIHI ‘l I II | \ III I l 3&2» IIHHI‘HH HYDROXY-"ACIDS FROM CELLULOSE DECOMPOSITKON hosisi’or {has Dawes ai‘ M‘ 3. MECHEGAN STATE COLLEGE Wen Tab Tsiang 1947 -- i. . --..41J.t..«l.1fl. I I I..- 2..-ll.. .111, All . . .< .l, ,5 . . l‘..fi1Jfil§d .k .. IIICRDFILH BY CONTACTING - HIS DOCUL-EHT ARE AVMIABLE 01: AND murmurs I no. ; ‘ . -. -18 guys.“ “Fm .‘Dlylm .05.}, Arm. TSIVAD Thisistoeertflgthatthe thesis entitled HINDU-ACIDS FROM CELUIDSE DECOHPOSI TION presented by Wen TAH Tsiang hss been accepted towards fulfillment of the requirements for Wdegree WENGINEERING Major professor Bat 28 1947 HYDROXY-flCIDS FROM CELLULOSE DECOMPOSITION By W TAH TSIANG A THESIS Submitted to the Graduate School of'Michigan State College of Agriculture and Applied Science in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE Department of Chemical and metallurgical Engineering 1947 70/ 4 ,. / 7 35" S" '7' TABLE OF CONTENTS Acknowledgements Introduction Literature Review Experimental Procedure . Discussion Summary Bibliography l89055 Page 24 50 51 ACKNOWLEDGEMENT The author wishes to exPress to Dr. Clyde Colvin DeWitt and Dr. Richard Thurm his deepest appreciation and grat- itude for their unfailing guidance and suggestions which have made this invest- igation possible. INTRODUCTION Each year, in every country many tons of cellulose material is burned or is otherwise wasted. In the present processes of rayon manufacture, large quantities of degraded cellulose find their way to waste heaps, or they are burned to recover their po- tential soda ash content. The same type of degraded cellulose waste material is found in the effluent solutions from the brewing industry, the cellOphane industry, the ethyl-cellulose industry, the wood sugar industry, and from the manufacture of soda—pulp for paper manufacture. It has long been recognized that these solutions contain com- plex soluble mixtures of organic compounds derived from the degra-' dation of cellulose. Such materials are most always found in the form of the sodium salts of hydroxy-organic acids, or, in the case of the brewing industry, in the form of aliphatic diols. The grow- ing industrial importance of such compounds has quickened the efforts of many investigators toward work on their recovery. This interest has been enhanced by the insistence of State Conservation Departments that the stream pollution formerly prac- ticed shall be discontinued. Such efforts demand large capital ex- penditures; the operation and maintainence costs of such processes are likewise high. The reduction of these costs through recovery of valuable products heretofore discarded is clearly within the 5 province of the chemical engineer. This thesis presents a prelim- inary investigation of the nature of some of the products of pre- sent industrial value that one may expect to recover from such waste solutions. LITERATURE REVIEW It has been known that cellulose has a stronger resistance toward alkaline solutions than acid solutions. However strong alka- line solutions at high temperatures will dissolve cellulose to an extent depending upon the alkali concentration, the temperature, and the pressure used.(l) If the cellulose is treated with strong alkali solution in the presence of air or oxidizing reagents, the cellulose will be degraded with the formation of a lower molecular J weight cellulose chain. This reaction is utilized in the prepara- tion of regenerated cellulose fibres in the rayon industry.(2) This reaction is considered to be a Special kind of oxidation.(5) The chemical mechanism of the oxidative attack by strong-alkali is not clearly understood. It has been explained by H. A. Rutherford and M. Harris(2) thus: ”It would appear that the attack on cellulose by oxidizing reagents would be confined to three points in the anhy- droglucose residue of the cellulose chain: (1) The aldehydic end groups of which there are few if any in native cellulose could be oxidized to carbonyl groups. (2) The primary alcohol groups could be oxidized to the aldehyde group or carbonylic acid depending upon the oxidizing conditions. (5) The glycol group (the 2,5 dihy- droxy group) of the glucose residue could be oxidized with the for- mation of ketonic, aldehydic, or carboxylic groups depending upon the course of the reaction.” Typical possibilities for the pri- _ mary attack are formulated by H. Mark and M. Harris.(2)‘ 2/ \ c/ \ I T .. I o 3c\ /g—c-0H—°—'u c\ /c—<':'—0H . 4? ‘E I g 9 9 c c Hc|o{ \T Holso/ \ HOC-O o in studying the ageing of alkali-cellulose in the vis:osc process, one of the possible explanations for the mechanism of alka- ZLnic oxidation of cellulose has been scheduled as follows:(4) ongH (0 GD "—0 H 9 ‘3’ 0' H OH H10” H OH OH H —° c—ouo—o- (4) o HCOJ-I , cmon‘ 7 The action of strong alkali solution toward cellulose at high temp- erature and high pressure has been investigated by former workers. (5)(6) They found that cellulose can be completely dissolved in sodium hydroxide or potassium hydroxide solutions. In 1871 and 1889 HOppe and Seyler(5) treated Swedish filter paper with alkali about 9 N. The cellulose went into solution at 200.24000., with the formation of about 360 c.c. of gas per gram of cellulose. Most of this gas was hydrogen (86—8%); the solution contained formic, acetic, and other fatty acids. Later Fischer and Schrader treated filter paper with 47 grams of 4.1 N KOH and 27 grams of 5.0 N NaOH per 100 grams of cellulose at temperature zoo—50000.. A quantity of 002 equivalent to 9.5 grams per 100 grams cellulose was obtained and about 20 grams per 100 grams cellulose was obtained as formic, acetic, and lactic acid. The hydroxy—acids have been found in larger quantities by Fischer and Schrader.(7) Oden and Lindberg(5) reported that when the mixture of cellulose and caustic soda were heated in autoclaves to 372° C, pressure at 241 atmospheres, a yellow to brown, quite tranSparent solution was obtained. This solution had a strong odor of methanol and mesity- lene; it contained methanol, acetone, and various salts of organic acids. Oden and Lindberg(5) suggested that the first stage of decomposition was the Splitting up of cellulose into glucose which is known to yield lactic acid and in turn, the lactic acid would dissociate into ketones hy further reaction with caustic solution according to the following reactions: zcnscsmmcooua + 2NaOH——D (0}15)200 + 2112212005 + H20 + CH4 2CH50H(OH)COONa + moon —. czascssco + 320 + 31512005 + 112 Emil Heuser(6) and his co—workers found that when soda pulp was treated with a 17% caustic soda solution at a pressure of 8-10 atmOSpheres, correSponding to 171—18100, the cellulose was per- fectly dissolved after 647 hours. From this solution lactic acid could be isolated. No detailed information is available. Heuser (6)believed that the formation of lactic acid is preceded by that of other hydroxyl carboxylic acids of greater molecular weight, such as saccharic acids, which are isomeric with glucose, a de~ composition product of.cellulose£8) P. Klason(6) has found these acids in the waste liquor of the soda pulp mill. In the soda process for the manufacture of cellulose fibre from the wood, the lignin in wood is dissolved much faster and at lower alkali concentration than cellulose. However, the compara- tively low yield of cellulose-fibre by this process gives the evi- dence of the fact that considerable amounts of cellulose are also dissolved during the cooking period. The resulting organic acids are destroyed together with the dissolved lignin when the black liquor is burned to soda ash. H. Kiliani(9)(lo) and his co-workers reported on the alkaline decomposition of the disaccharides, dextrose, and laovulose with potassium hydroxide. They found an isosaccharinic acid. When this acid was treated with Ag(OH)2, acetic acid and glycolic acid were 9 obtained. 1,5 dihydroxy butyric and 1,2 dihydroxy butyric acids in (11)(12)(15) and his students its active forms were obtained by Nef in the course of their work on the effect of alkalis on the various sugars. Evans, Glattfeld, and their co-workers (14)(15)(16)(17)(27) have done considerable work on the alkaline degradation of sugars, 1.9., cellubiose, lactose, melibiose, and gentiobiose. They con- cluded that these sugars, when reacted with aqueous solutions of potassium hydroxide, gave lactic, acetic, and formic acids. These reactions may be eXplained by the endiol theory of chemical reac- tion in the disaccharides. The isosaccharinic acid and dihydroxy butyric acid have also been prepared by treatment of oxycellulose with lime water. Both of these acids were obtained by Sccarachmidt and Nowak(18) by the action of nitrogen tetroxide on cellulose. Since the cellulose contains cellubiose units, the treatment of the cellulose with acetyl bromide and glacial acetic acid has shown the existence of the cellubiose.(l)(lg) Therefore, all the acids which have been found in degraded disaccharides may be looked for in the alkaline solution degradation products of cellulose. In all the previously reported work on alkaline degradation products of cellulose-like materials, the identification of these products has depended solely upon the preparation of relatively impure calcium, sodium, zinc, or silver salts. High temperature, vacuum distillation, and selective, solvent extraction have failed 10 to give decisive separations of the hydroxy acids such as lactic, glycolic, dihydroxy-butyric, and hydroxy-vnleric acids. Scone of Present Investigation The object of this investigation was to prepare derivatives of hese hydroxy acids from the foregoing cellulose solutions, in the hOpe that these derivatives of organic hydroxy acids might be sep- arated by distillation. The identity of the compounds separated by distillation was then proven by analytical methods. The present work indicates that the acetylation of the cellup lose syrup with acetyl chloride appeared to be the most feasible way for isolating these hydroxy acids by distillation methods. Acetylated derivatives of glycolic, lactic, and dihydroxy- butyric acids have been obtained. Primary identification has been made by boiling point range of distillates and by molecular weight determination. Barium content of reapective salts has been deter- mined. Carbon and hydrogen content of each of these acids has been checked. The fact that the boiling points of these acotyl hydroxy acids are close to each other makes it quite difficult to prepare by dis- tillations very pure fractions. This phase of our problem needs further attention. EXPERII'YTAL PROCEDURE (1) Ereparation‘gf alkaline solution‘gg cellulose. 171.1 grams of cotton linter with 5—4% moisture content was placed in a steel autoclave previously charged with 271 grams of 25.8% caustic soda in 450 grams of distilled water. The cotton linter was thoroughly mixed with the alkali solution. The autoclave was clos- ed and heated electrically to a temperature of 480°F. (250°C.) for six to ten hours; then cooled to room temperature. No gas was gen- erated. All the cotton linter was dissolved. The solution had a yellowish to brownish color and possessed a characteristic odor. Different sources of cellulose, i.e., absorbant cotton, washed rugs, filter paper, and cotton linter have been used in these experiments. The same type solutions were obtained,in as far as their appearances were concerned. When the cooking temperature was lower than BSOQF. (177°C.), a suSpension of tiny fibres was observed. This indicated the incompleteness of cellulose dissolution. The influence of cook- ing time upon yields of hydroxy acids was not investigated. (2) Treatment-g: cellulogg solution pith formaldehyde. Murray Senkus(20) has isolated the 2,5 butanediol from beer by treating it with 50% H2804 and 56% formaldehyde. The hydroxyl groups on carbon atoms alpha and beta to each other in the butanediol react' with formaldehyde to form 2,5 butanediol formal which can be dis- tilled off over the boiling range, 97-10200. When the cellulose was dissolved in alkali solution, the dihydroxy acids such as 2,5 12 dihydroxybutyric acid, dihydroxy valeric, or isosaccharinic acids, etc., were possibly formed. If any of these dihydroxy or poly hy- droxy acids existed in cellulose solution, it was hoped that they might form the formal compound with formaldehyde in presence of sulfuric acid. ' 600 grams yellowish cotton solution from the autoclave was neutralized with 50% sulphuric acid. The evolution of gas in neup tralization showed the presence of carbonate in the alkali solution. .A small amount of pitch floated on the top which could easily be filtered from the cool solution. To the filtrate 20 grams Norite was added to effect decolorization. A nearly colorless filtered solution was obtained. The formic and acetic acids were separated by steam distillation. The distillation was carried on until the distillate showed but a trace of acid. (A small amount of lactic, and glycolic acid always came off with the steam.) To the residual solution, 50 c.c. of concentrated sulphuric acid and 100 c.c. of 36% formaldehyde were added. This mixture was refluxed at 100°C. for three hours, and then distilled with steam. No product was obtained. Another batch of cotton solution was neutralized with 50% sulphuric acid, and filtered, and decolorized just as before. The clear solution was concentrated by distilling off 500 c.c. water. 200 c.c. of concentrated solution was mixed in a round bottom flask with 100 c.c. of 56% formaldehyde. The flaSk was provided with re- flux condenser and a dropping funnel. 50 c.c. of concentrated 13 sulphuric acid was dropped through the funnel into the mixture. The mixture was refluxed for about five hours. Distillation of the mbe- ture gave no product. These eXperiments while negative in.giving the desired separa- tion, showed that the essential nature of the diol separation is sib— stantially different in mechanism than the previous investigators work seemed to indicate. (5) Acetylation g: gellglgsgugyggp with acetylchloride. 1600 grams of sulphuric acid neutralized cellulose solution in. which 500 grams of cotton linter has been dissolved was decolorized with Norite, and the solids filtered. The clear solution was evap- orated in a vacuum at a temperature of 70-8000. until a yellowish syrup was formed. The syrup was extracted from inorganic salts with 90% methyl alcohol. The methanol extract was distilled on a water bath. When all solvent was driven off, several 50 gram lots of glacial acetic acid were added and distilled off under vacuum. When the density of the distillate reached that of pure glacial acetic acid, all of the water remaining in the syrup had been carried off with acetic acid vapor. 150 grams acetylchloride and 10 grams an— hydrous sodium acetate were then added to the dried syrup; the mix- ture was refluxed gently on a water bath for about five hours. The reaction mixture was dissolved in glacial acetic acid; the undis- solved solids, most of which are sodium chloride, were filtered. The filtrate was distilled in a vacuum on an oil bath at about 250° C. When all acetic acid had been distilled off, the temperature l4 raised suddenly, and a colorless to slight yellow liquid began to come off at 120°C. at 12 mm. The distillate of boiling point range from 120°C. to 170°C. was collected. The weight of crude oil was 55 grams. The total yields of these acetyl hydroxyl acids is about 18% based on the total weight of cotton linter charged. The crude oil was redistilled in vacuum. Three fractions were obtained. The Specific gravity of each fraction was deter- mined (Table 2). Hydrochloric acid in place of sulfuric acid was used in a similar neutralization of the solution of cellulose. When the same procedure noted above was used, no vacuum distilled product was obtained. In this case the acetylation was carried out with acetyl chloride in the presence of dry hydrochloric acid gasS21)(27) 15 soapsaom H mamaa mpmameoo .oooow .mhfl wH I c a a s a C NH seeded mcfipchmSm Spas soapfiflom .OOOmv .mhz m c c s t I c O HH scepsaom eeeeaee seesmaa .oeoma .eas e e e a sea sea a s OH .nHom em.m~ assess . s .oeome .ess me was one new Haw ass Had deeeee m soapdaom pm nomad sseaee seesaaa .eeOma .eas a saw ooe esm me see oea aeeaae m hawo once soap mmmh usaee geese .oeome .eas we saw ooa saw me was oea assess a e . .oeome .eas we saw com . mam oma . m afiee sees: eeseaee sesamaa .oeome .eaa He saw ooe saw we saw cad aeeeee m Hmaeepms pHHOm soepoo muses duos .ooome .man mm new 00w mam mu mam oma 3mm v .saee awn . . .eOOme .aas ea new one saw so» saw one s e soapsaom new: IBOHD mpmHmEoo .ooomw a c v I v t I I I N mmnnfim msfiwscm compoo .zese seas seeps emu seen :Hee seassean .onme .ees ma new cow was com mam ooa unease H ymsaaeeo eases moez seesaw Hess it; no ease sees me me :Heo we noses .ez asassem assesses msaesem passes sawed; sesame sex ass 16 TABLE II Fraction No. . Boiling temperature Specific gravity at at 10-15 mm. vacuum 25°C. 15 128-1300C. 1.1767 B 150—145°C. 1.1771 c 145-148°c. 1.1776 ANALYSIS (1) Preparation 9:.bggium ggltgg Weigh out one gram of each acetylated hydroxy acids from the above distillation fractions. Titrate the acid with 0.57 NBa(0H)2 at a temperature, 5-5°C., using phenolphthalein as indicator. The red color of indicator will fade gradually on standing. (This may be explained as caused by the hydrolysis of the small amount of lactone existing with the hydroxy acids. When in alkali solution the lactone ring of acid opens to form the corresponding hydroxy acid.) Then to the solution, add 50 c.c. excess Ba(OH)2, and re- flux gently for several hours. The residue is neutralized with 0.50 N sulphuric acid, and an excess is added. Distill off the ace- tic acid with steam until the final distillate shows very slight acidity. Filter off the BaSO4. Exactly neutralize the clear fil- trate with Ba(0H)2 to a point where neither barium nor sulphuric and shows its presence. Evaporate to dryness at 100—1é000. An amOphor- ous salt of barium is obtained. .Analyze for the Be content of this salt 0 Barium Contents: Fraction A Weight of crucible and sample Weight of crucible Weight of sample Weight of ash (as BaSO4) and crucible Weight of crucible Weight Of 351304 weight of Ba % Of Ba 0.1758 X 100 0.4155 Weight of Ba 5 of Ba 0.1706 X 100 0.4024 Fraction B Weight of crucible and sample Weight of crucible weight of sample Weight of ash (BaSO4) and crucible Weight of crucible Weight of BaSO4 152.56 0.2988 X 255.42 0... x 157,56 ?900 266.42 I 15.5657 gms 15.1514 0.4145 15.4502 15.1514 0.2988 3 0.1758 gms = 42.45 = 0.1706 gms = 42.40 I 15.5746 gms 15.1501 0.2245 15.5182 15.1501 0.1681 II 16.4505 16.0479 0.4624 16.5579 16.0479 0.2900 II 15.4244 15.1505 0.2741 15.5545 15.1505 0.2040 17 gms ng Weight of Ba 18 0.1681 x.1§Ze§§ = 0.0987 gms 25 2 % of Ba W47. 1 100 = 45.95 0.2245 Weight of Ba 0.2040 X.l§2&§§.= 0.1200 gms 255.42 0.2741.X = 45-78 Fraction C I II Weight of crucible and sample 16.2716 gms 15.5968 gms Weight of crucible 16.0451 ’ 15.1506 ' Weight of sample 0.2285 ' 0.2462 ‘ Yeight of ash (BaSO4) and 16.2111 ' 15.5555 I crucible Weight of crucible 16.0451 ' 15.1506 ' Weight of Beso4 0.1680 -’ 0.1827 ' Weight of Ba 0.1660 x lfilséfi = 0.0990 s 255.42 gm -5:§§§§rx‘ - 45.28 Weight of Beso4 0.1827 x l§14§§ = 0.1074 gms % of Ba 255.42 0.1074 x 100 _ 7 0.2462 ‘ 40°60 19 (II) Determination of molecular weight - by Beckmann's Freezing Point Depression Method. Use glacial.acetic acid as solvent which has a constant 5.90. M = 1000 ng ATf _G “' Fraction 2 I II G, Weight of acetic acid 25.6276 gms 28.2575 gms g, Weight of acetyl acid . 0.7650 gms 0.5687 gms T1 4.475 00 2.175 00 T2 5.400 00 _ 1.752 00 _.1Q90 x 5.90 x 0-722. _ M “ 1.075 x 25.6276 ‘ 116°9 __1000 x 5.90 x 0.5687 _ M ‘ 0.445 x 28.2575 ‘ 115°° Fraction B I II G, Weight of acetic acid 27.9000 gms 29.8545 gms g, Weight of acetyl acid 0.5985 9 0.4120 ' T1 2.152 00 2.012 °c T2 1.750 °c 1.645 06 [STf 0.582 °c 0.569 °c M = 1000 x 5.90 x 0.59_8_5 = 46. 0.582 X 27.9000 1 1 ' 0.569 x 29.8545 = 145’9 Fraction 0 y ' I II G, weight of acetic acid 51.4060 gms 29.9745 gms g, Weight of acetyl acid 0.5095 ' 0.4572 ” T1 2.070 00 2.125 00 T2 1.650 ”’ 1.725 ' ATf . 0.440 1' 0.400 a M = 100042 5.90 x 0.5095 = 143.7 0.440 x 51.406 = 1990 x 5.90 x 0.4572 3 M 0.4000 1: 29.9745 ”1'1 (III) Determination of carbon and hydrogen contents by combustion method . Fraction A The acetyl group in the lower hydroxy acid is apt to be hydrolyzed when it stands a long time at room temperature. The carbon, hydrogen determination of the first distillation fraction is determined on the barium salt instead of the oily acetyl liquid. Weight of sample and boat 5.7101 gms Weight of boat 5.6277 gms Weight of sample 0.0824 gms Weight of Ascarite tube after combustion 65.6766 gms Weight of Ascarite tube before combustion 65.6242 gms Weight of 002 0.0524 gms Jeight of Dehydrite tube after combustion 56.2215 gms Weight of Dehydrite tube before combustion 56.2005 gms Weight Weight Weight W eight Weight Weight Weight Weight Weight Weight of H20 __ 0.0208 x 0.1119 _____ 9 n it 5 c = 0°05“; 3‘ 5‘ x 100 = 17.47 0.0824 x 11 of sample and boat of boat of sample of Ascarite tube after combustion of Ascarite tube before combustion Of 002 of Dehydrite tube after combustion of Dehydrite tube before combustion of H20 % H = ongfig’i‘OO-lufi x 100 = 2.96 5 c = 0'0579 X 5 x 100 = 17.55 0.0910 x 11 Fraction B (Determined by oily acetyl acid) Weight Weight weight Weight Weight of sample and boat of boat of sample of Ascarite tube after combustion of Ascarite tube before combustion * The correction for Ba005 is negligible. 0.0208 65.7840 65.7261 0.0579 56.2652 56.2411 0.0241 5.9016 5.7281 0.1755 62.5428 62.2554 21 gms ng gms gms gms ng gms gms gms gms ng gms gms Weight of 002 Weight of Dehydrite tube after combustion Weight of Dehydrite tube before combustion Weight of-HgO % H 3 0.0875 X 0.1119 X 100 :3 5.65 0.1755 _ 0.2894 x 5 _ % C “ 0.1755 x 11 x 100 “ 44‘96 Weight of sample and boat Yeight of boat Weight of sample Weight of Ascarite tube after combustion Weight of Ascarite tube before combustion Weight of 002 Weight of dehydrite tube after combustion Weight of dehydrite tube before combustion Weight of H20 _ 0.0890 x 0.1119 _ % H ~ 0.1917 x 100 u 5.19 $0-9:W X100 344.65 _ 0.1917 x 11 Fraction 0 (Determined by oily acetyl acid) Weight of sample and boat Weight of boat 22 0.2894 gms 56.5817 gms 56.2944 gms 000875 gms 5.9155 gms 5.7258 gms 0.1917 gms 62.8581 gms 62.5444 gms 0.5157 gms 56.4026 gms 56.5156 gms 0.0890 gms 5.9501 gms 5.7287 gms Weight Weight Weight Weight Weight Weight Weight Weight Weight Height Weight Weight Weight Weight Weight Weight of sample of Escarite tube after combustion of Ascarite tube before combustion Of 002 of Dehydrite tube after combustion of Dehydrite tube before combustion of H 0 2 __0.1097 x 0.1119 g H ‘ 0.2014 X 100 _ 0.5451 x 5' % C ‘ 0.2014 x 11 x 100 of sample and boat of boat of sample of Ascarite tube after combustion of Ascarite tube before combustion of CO2 of Dehydrite tube after combustion of Dehydrite tube before combustion of H20 0.2087 g 0.2087 x 11 x 6.09 ‘ 46.46 6.28 46.71 0.2014 47.4811 47.1580 0.5451 56.5814 56.4717 0.1097 5.8548 5.6261 0.2087 47.8079 47.4501' 0.5578 56.7889 56.6718 0.1171 gms gms gms gms gms ng ng gms gms gme gms gms 24 DISCUSSION From all the facts available it appears improbable that at the low temperatures employed for the dissolution of cellulose by caus- tic solutions any deep pyrolytic decomposition of cellulose will take place. Evolution of gases indicating such violent and unpredictable decomposition are only encountered if the reaction temperature ex- ceeds 275°C. to 500°C. But, when the cellulose is treated with a caustic solution at a temperature around 200°C. to 250°C. in a clo- sed vessel, the cellulose completely goes into solution. .A small amount of pitch and a light color of cellulose solution may indi- cate that rather smooth and normal reactions take place during the cooking. The mechanisms of these reactions is not yet clear. The dissolution of cellulose involves: (l) The cellulose molecules are first hydrolyzed into simple cellubiose or glucose units. (2) These cellubioses or glucoses formed may be immediately oxidized into acids or decomposed into lower-carbon acids by intra- oxidation. (5) Intramolecular rearrangement would take place resulting in the formation of hydroxy acids. ' I The theoretical equations which may represent the formation of hydroxy acid from cellulose solution are suggested as following: (22) (1) (06H1005)' 12120 50330003 cellulose acetic acid 25 (2) (Cefiloosb Hgo—pmmscmos) 00011 Lactic acid . .7" (5) (CeHioosv Hzo—ucsscmon) CH(OH)COOII + 01-000011 dioxybutyric acid acetic acid (4) (0611100 5)+ 1120 —- CH20H(OH) CH(0H) CH(OH) CH2000H isosaccharinic acid (5) (0631009-. ————.- CHSCHZCMOH) 011200011 + 002 mono-oxy valeric acid . (6) (06111005) -—-——->- cascazcsmmcmomcoon + 1100011 dioxyavaleric acid formic acid (7) (0631005) ——'- HOOCCH 2011(03)0H20H2000H - mono-oxy adipic acid (e) 200631009). 3120*3cescn(0n)ca(on)coou di-oxy butyric acid (9) (06111005)+ H20 -—-0H2(os)000Hv+ cascszcswmcoos glycolic acid mono—oxy butyric acid fill reactions prOposed above may take place at the same time. It seems reasonable at this time to believe that under the differ-7 ent conditions used in the solution of cellulose, 1.9., tempera- ture, strength of alkali, cooking time etc., different reactions might take place, or a particular reaction or group of reactions may dominate the overall result so that the formation of a particup lar hydroxy acids will be favored. From all results obtained in the work reported here, three hydroxy acids have been found, namely glycolic acid, lactic acid, and di4hydroxy butyric acid. All these acids were recovered as acetyl compounds. 26 Although the molecular weight, carbon and hydrogen contents, and barium content of each salt from each fraction have been deter- mined, a more accurate result will depend primarily on better tech— niques of separation of the acetylated acids. The following facts are of significance: (1) The boiling points of these acetyl compounds are very close to each other. Therefore the obtaining of a Very pure come pound by vacuum distillation is quite difficult. (2) The calculated value of carbon and hydrogen content in each of the acetyl derivatives are likewise close to each other. Any analytical error would lead a wrong interpretation. (5) All these compounds have almost.the same appearances, i.e. colorless oily liquids, pleasant odor, etc. They have almost the same Specific gravity. Therefore the method used for identification of hydroxy acids in this report can only be considered as a preliminary step which should be followed by further experimental work. In comparison with the experimental results with all constant available, the first distillation fraction is principally acetyl glycolic acid (CH3COOCH2000H). The molecular weights determined from this eXperiment are a little lower than that of calculated value. This may'shon the presence of a very small quantity of ace- tic acid Which has decomposed from its acetyl compound. 27 Fraction.£: Expgrimental Theoretical Molecular 116.9, 115.0 118 weight Ba content of 42.45, 42.2% 47.7% free oxy acid Carbon content 17.55, 17.47% 16.7% in Ba salt Hydrogen content 2.96, 2.82% 2.1% in Ba salt . 9* Boiling point 128 - 150°C.12 145°c.l" Density 1.1767 at 25°C. 1.0995 at 1700.it (25) * based on R. Anschutz's eXperiment The fraction B which has boiling point range 150—14500. at 10-12 mm. vacuum has been found to be a mixture of acetyl lactic acid and acetyl dioxybutyric acid. .And the percentage of each of these acids is interpreted based on their molecular weights. About 85% of acetyl lactic acid and 15% of acetyl dioxybutyric acid are found in this fraction.~ Fraction B: Experimental Theoretical Pure Aceto Pure Aceto Mixtugef* Lactic Dioxybutyric Molecular 145.7, 141.1 152 204 142 weight Ba content of 46.1, 45.6 45.6 56.5 42.6 salt free acid Carbon 44.96, 44.65 45.42 47.1 46.55 content Hydrogen 5.65, 5.19 6.06 5.90 6.02 Content Boiling 150-145°c.(12) 127°Cll(24) 127°c.4(25) -- point Density 1.1771 at 25°C. ....... ...... .._.. 28 ** Calculated as 85% acetolactic acid and 15% diacetyl dihy- droxy-butyric acid. The fraction C also contains acetyl lactic acid and diacetyl dihydromy - butyric acid, with about 80% of the former and 20% of the latter. Fraction C Experimental Theoretical ** Pure Aceto Pure Aceto mixture Lactic Dioxybutyric Holecular 146.1, 145.9 152 204 146 weight Ba content of 45.28, 45.60 45.6 56.5 42.2 Salt free oxy acid Carbon 46.46, 46.71 45.42 47.1 45.7 content - Hydrogen 6.09, 6.28 6.06 5.9 6.02 content **Calculated as 80% acetyl lactic acid and 20% diacetyl dihydroxy - butyric acid. 1 The results listed in the above tables are estimates which are based on the known presence of the compounds in question. The boiling points of all the.aceto-hydroxy acids under investigation are so close to one another that a given fraction may contain more than two hydroxy acids. Therefore, it seems quite probable that the higher hydroxy.acids, other than dihydroxy-butyric acid may be found in the distillation residue which begins to polymerize and decompose at a temperature above 148°C. Better vacuum distillation 29 techniques are indicated as a possible solution for this problem. Future work in this field may well be confined to the waste solutions obtained from the soda pulp paper industry which daily discards hundreds of pounds of the hydroxy acids in the form of an alkaline solution. . It is possible to replace the hydroxy groups by hydrogen atoms through reduction with hydriodic acid‘9)(lo) This reduction.has been reported.(28)using sodium ammalgam. Phosphorous iodide like— wise has been used for this purposeEZG) These methods of reduction were not used in the present investigation because it was felt that large Operations would not be feasible with such reagents. The results of the present investigation indicate that Aushutz(25) data on the boiling point of acetyl glycolic acid is in error. He reported for this compound a lower boiling than that of acetyl lactic acid. 50 SUMMARY (1) When cellulose is treated with 10% sodium hydroxide solution and heated to a temperature about 250°C. in an autoclave, it will completely go into solution. (2) When the clear and dried cellulose syrup is acetylated with acetyl chloride in presence of anhydrous sodium acetate, a colorless, oily-like compound is obtained by vacuum distillation of the reaction mixture. It has a boiling point range from 120°C. to 148°C. (5) The molecular weights, barium content, carbon and hydro- gen contents of each distillation fraction of these compounds have been determined. (4) Clycolic acid (hydroxy-acetic acid), lactic acid (hydro- xy propionic acid) and dihydroxy'butyric acid have been found in the alkaline'solution of cellulose. (4) The contents of each distillation fraction are estimated by interpretation of their average molecular weight, the barium content of the barium salts, the carbon.hydrogen content of the barium salt of the lower boiling fraction, and also of higher boil— ing fractions of the oil—like acetyl compounds. (l) (2) (5) (4) (s) (e) (7) (a) (9) (10) (u) (12) (15) (14) (15) (16) (17) (18) (19) 51 BIBLIOGRAPHY Gilman, “Organic Chemistry”, Vol. II, pp. 1864. Ott, Emil, “Cellulose and Cellulose Derivatives', pp. 151. Heuser, E., 1"l‘erct‘oook of Cellulose Chemistry”, pp. 121. 3The Mechanism of the Ageing of Cellulose“, unpublished. report by Riordon Sales Corporation, Ltd., Canada. Oden and Lindberg, Ind. Eng. Chem., 19, pp. 152 (1927). Heuser, E., Paper Trade Journal, pp. 129,(December 26, 1929). Fischer and Schrader, Abhandlungen Zur Kenntnis Der Kohle, Vol. V, pp. 550 and Vol. VI, pp. 115 (1925). Heuser, E., Lehrbuch Der Cellulose Chemie, pp. 129 (1927). Kilani, H. and Kleemann, 5., Ber. Der Deu. Che., 17, pp. 1500, use) . . Kiliani, H., Annalen Der Chemie, 217-218, pp. 561,(1885). Nef, Annalen Der Chemie, 217.218, pp. 1-120 (1910). Upson, J. Am. Chem. Soc., 45, pp. 458 (1911). Raske, Ber. Der Deu. Che., 45, (1912). Evans, W. L., and Hockett, R. C., J..Am. Chem. Soc., 52, pp. 4584 (1951). ' Evans, Edger, and Hoff, J. Am. Chem. Soc., 48, (1926). Evans and Benoy, J. Am. Chem. Soc., 52, pp. 294 (1950). Glattfeld, J. W. E. and Sander, F. V., J. Am. Chem. Soc., 45, pp. 2575 (1921). ‘ Scharrschmidt, Novak, and Zetzshe, Der Papier Fabrikant, Vol. VII, pp. 590—591 (1929). Tollens and Elsner, 'Kurzes Handbuch Der Kohlen—Hydrate“, pp. 456 (1955). (26) (27) (28) 52 Murray Senkus, Ind. & Eng. Chem., 58, pp. 915 (1946). Glattfeld, Chitten, J. Am. Chem. Soc., 55, pp. 5665 (1955). The author is indebted to Dr. R. Thurm's valuable suggestions. Anschutz, R., Ber. Der Deu. Che., 56, pp. 466 (1905). Auger, Compt. Rend., 140, pp. 958 (1905). Glattfield and Straliff, J. Am. Chem. Soc., 80, pp. 1585 (1958). Lantemana, Edward, Annalen Der Chemie., 115-114, pp. 217 (1860). Ref, Hedenburg, and Glattfeld, J. Am. Chem. Soc., 59, pp. 1658- 1652 (1917). Marguard, Ber. Der. Deu. Chemie., 2, pp. 585 (1869). Nw27 '41 |. |It l'llt : 4" [q 1 T O 01 1 mo #5 n us KL) -) I; 189053 Tsieng Tsinn” Hydroxy-ecids from cellulose as s 31293 02446