ELASTYC lug. . atl‘ A "3 tlg"’ ~ ‘ :0 “‘3 . ' . '3- I‘; 0.’ . W‘s .' --_ This is to certify that the thesis entitled A STUDY OF ELASTIC BEHAVIOR OF "IOOL presented by Balwant Rai Suri has been accepted towards fulfillment of the requirements for __M...S.._degree inflhemisin; Date Jul}r 30, 1981 Major professor - w / .T U t. [I fl‘ rif‘. 4' III {f I [l l .I'l (I'll-l . . L L (I III\ I: II It ( Ill! ‘ It I! ill. «I . u . . E ‘ [ ‘ .r‘ll‘ ‘ I I'll ll A STUDY OF ELASTIC BEHAVIOR OF WOOL By Balwant Rai Suri A THESIS Submitted to the School of Graduate Studies of Michigan State College of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Chemistry 1951 f? . , ACKNOWLEDGMENT To Professor Bruce E. Hartsuch, the author wishes to express his sincere appreciation and gratitude for the guidance, many helpful sug- gestions and for the never failing encouragement that have made possible this work. ********** *s*##*** ****x* **** ** * CO NTEQ N '1. S PAGE III\JAPEEO£)UC'.FIOIJOO.00.......0.0..O.0....COCOOOOOCOOOIOCOOOOOOO l CHEMICAL STRUCTURE OF WOOL................o......o......oo 3 LII‘IKAGISS I}; YEFOCD‘LOOOOOOOOOO.000......OOOOOOOIOOOOOOOOOOOOOO 14 CEEIIICJ‘L PROPliTIBS OF ViOOLOOOOOOO9000.00.00.00.0.0.0.0.... 16 BUILDING OF LEW CR SS‘LINKAGESooooooooooooooosooeooooooooo 21 ICXiJE‘l‘LIFifijld'EAIJOOOOOOOOOOOOOOOOOOOOOOO00.00.000.000...0...... 242 RESIJLTSOOOOOOOOOOOOOOOOOOOOCOOOOOOOOOOOOOOOOOOOOOOOOIOOOOO 27 DISCUSS-SLOIJ OF RESULiPSOOOOIOOOOOOOOOOOOOOOOOOO0.0.0.0000... 66 The Contractile Behavior 0f1W0010000.000000000000000. 69 The Stretch Behavior of Wool Yarn.................... 73 Effect Of Load on Stretch and Time................... 75 Final condensed ResaltSooooooe0000000000000000000000. 78 BIBLIO(}E{_APIIYOI0.0.0.0000...OOOOOOOOCOOOOOOOIOOOOOOOOOOOOO. 80 INTRODUCTION The main textile fibers fall into three groups -- I- vegetable origin (cotton, linen, rayons), II-Animal origin (silk, wool) and III- synthetic fibers (nylon, vinyon, saran, vicara, and orlon). Wool is the oldest and most important animal fiber, and is used mostly for outer wear. It has all the essential properties for a textile fiber; its length is good and its fineness superior; its serrated sur- face gives it good spinning quality; its strength is sufficient for the purpose for which it is used and it is soft and elastic. Wool differs from other textile fibers because of its long range elasticity, that is, its ability to recover from deformations of magni- tudes considerably greater than those permitted by other types of fibers. The elastic property of wool is similar to that of rubber, since both can be stretched by some force and return to the original length or shape when released from the stretching force, provided the breaking point has not been reached. It can be stretched in very 20 found that this stretch can be dilute NaOH solution and Speaksman completely recovered after some time. wool is a complex protein fiber which can be hydrolysed by caustic alkalies and reduced with reducing agents such as thioglycollic acid and sodium.hydrosulfite. It can be oxidized by oxidizing agents such as KMnO4. The present work has been undertaken to study the elastic behavior of wool when it is subjected to different stretching loads at different temperatures in alkaline solutions of different concentrations, and solutions of reducing agents. wool yarn has been subjected to these conditions, and the relations among stretch, contraction and time of contact have been determined. CHEMICAL STRUCTURE OF‘WOOL Wool is an animal protein fiber, forming the protective covering of sheep. Analysis shows that it contains carbon, hydrogen, oxygen, sulfur and nitrogen. The percentage of nitrogen varies from 16.5 to 17.1 percent. This is fairly constant but not as much so as it is in silk. The percentage of sulfur varies from 3.1 to 4 percent. The variation in the amount of sulfur in different wools not only affects the quality of the wool, but also indicates the variation in the sulfur containing component of wool protein. During processing, wool may be exposed to the action of acids and alkalies as well as acidic and alkaline oxidizing and reducing agents, and changes in nitrogen and sulfur content are inevitable. Ordinary wear and tear also results in a change in the amount of sulfur and nitrogen in wool. When'wool is hydrolyzed with alkalies a mixture of salts of seva eral amino acids is obtained, and wool is considered to be composed of long chains of condensed amino acids; any one of which may be repre- sented by the general formula: H ‘ i H2N-§- COOK It is apparent that such a structure may exist in two spatial configurations: 4 QH p. 2 L‘U-‘Od m H i H N-C-COOH or H000- R It is apparent that these amino acids are amphoteric, since they contain a basic amino group (-NHZ) and an acidic carboxyl group (COOK). Therefore two molecules of amino acids may react to form a salt like an ammonium salt, the ions of which may then condense, with the elimi- nation of a molecule of water. This is shown by the following equations: - + if R2 iii R2 I l ' V-C-CC 1 f - -C' 2 T -‘- - -C H211 ‘ JO i+ izN ('3 OOH HZN (ll COO + 3N (i OOH R1 H Rl H I: 1:2 I: 32 H N-C-COO 4- H N-C-COOH 2 H N-C-CO-NH—C-COOH - H 0 R1 H R1 H In such a manner many molecules of amino acids may be condensed to form.a long polypeptide chain which might be represented by: H 3 R2 3 H 5 R4 - ' i.~ \ E-. l E & -Hh-C-Coth-C-COTNH-C-COTNH-'-CO- R1 : : R3 : H The parts enclosed by dotted lines represent the various amino acid residues or components. Speaksmanl 8 has shown that the polypep- tide chains of wool contain as many as 576 amino acid residues. . o . Since valence angles around carbon atoms are 109 , the preceding chains of atoms may better be pictured as a zig-zag chain such as 32 C 'H /\ '\ H H ‘ , E C EH CO I l R1 R5 Wool fibers consist of many such polypeptide chains lying fairly parallel to each other. They are probably entangled with each other and this would contribute to the strength of the fiber. There are other factors that help to hold the chains together, such as hydrogen bonding, which could become operative between a carbonyl group of one chain and an amino group of an adjacent chain. This is pictured as follows where the hydrogen bond is represented by vertical dotted lines. é i N\ /C O H N C \/\/ \ __/ \ Hydrogen bonding causes the main chains to lie on top of one another at a certain regular distance, and the side chains (represented by'Rl, R2 and R3) stick out on either side. The main chain is a H regular repetition of -8—hH—C- units. Individually these bonding forces are not very great, but the combined effect of a large number of them.can be considered to tie the chains together in a different way. If an R in one chain has a basic group at the free end, and the R of an adjacent chain has an acidic group at the end, they can attract each other and form an electrovalent bond or salt linkage between the two chains. The relative proportion of each amino acid in wool can be deter- mined by dividing the percentage of each by its molecular weight. Eighteen amino acids have been isolated from wool protein. They are tabulated in Table I. It is possible that more are present. The groups in the second column takes the place of R in the general formula H i R-C-NHZ COOH The third column in the table shmws the fraction of each residue in wool, and the sum total of all the residue frequencies is equal to one molecule. There are three amino acids in wool which contain (OH) groups; they are serine, threonine and tyrosine. They provide polar side groups on the protein chain, and attract other polar molecules. Amino acids in which the R groups are hydrocarbon chains repel polar mole- cules such as water, salt, acids and bases, and attract non-polar TABLE I AhiRO ACTDS 0F WOOL AND THEIR RESIDUE FREQUENCIES (Consden7) Name Formula Approximate ' Residue Frequency Glycine H- 1/io Alanine CHQ- 1/to Valine (ch3)2-CH- 1/24 Leucine (CH3)2CH-CH2- l/ll.5 Iso-leucine CHS-Cfig—CH(CH3)- Phenylalanine CGH5CR2- 1/45.5 Methionine Chg-s-csz-ceg- 1/206 Cystine HOOC-CE(KH2)-CR2-S-S—CH2- 1/b Pyroline gag -— CH2 1/i7 K2 ‘H-COCH (comp. form) ‘\ NH’L Tyrosine . HO-CGR4-CH2- 1/37 Serine HO-Chga- 1/i1 Threonine CHs-CR(OH)— 1/18 CH2- Tryptophan N) 1/1 65 Arginine HEN-C(NH)-Nh(CH2)3- 1/i7 Lysine NHZ-(CHZ)4- 1/53 Histidine HQ ==q-CH2- 1/206 HN in Aspartic Acid HOOC-CHZ- 1/i8 Glutamic Acid HOOC-CHZ-CHZ- l 9.5 molecules such as hydrocarbons. Amino acids containing a basic R group are arginine, lysine and histidine; such side groups can combine with acids. Amino acids containing an acidic R group are aspartic and glutamie acids; they can combine with bases. Cystine is one of the most important amino acids in the wool mole- cule. It is a diamino-dicarboxylic acid in which there is a disulfide linkage between two methylene groups. Its formula is: HCO NHZ CHJEESuS-CHZ-CH HEN coon The amino and carboxyl groups of cystine are involved in condensa- tion with two adjacent polypeptide chains, thus acting as a link between the two chains. This is shown as follows (3() lil- / NH v-q \/ ::>CH—CH2-S-S-CHZCH CO \\\ H CO .H /i \ combined cystine It is seen that cystine in wool fibers must contribute very defi- nitely to the longitudinal strength of the fiber, because it binds two parallel peptide chains with a bridge in which atoms are joined by strong primary covalent bonds. If these disulfide cross-linkages occur periodically in a manner similar to the rungs of a ladder, they must be associated with such physical fiber properties as strength, elasticity, elastic recovery, rigidity and pliability. Astburys’4 and Woods proposed the first working model of wool protein. Their structure showed the polypeptide chains of wool in a folded form.which would unfold when stretched, and then, owing to contractile forces, assume the original folded form.when the stretch- ing force is released. The structure assigned to wool in this first model had a hexagonal shape. It was not a satisfactory structure be- cause it failed to explain some of the well-known properties of wool. In 1941, Astbury2 and Bell proposed another structure, which seems to be quite satisfactory. This structure can.assume two forms, the normal relaxed or folded form, and the extended form.which results when the folded form is stretched. The two forms are shown on the following pages. The two figures show three cross linkages, two of the salt type and one cystine type. The relaxed form shows the cystine linkages joining parallel chains in the narrow sections of the folds, and the salt linkages, because of the longer side chains, joining two parallel chains at the bulged parts of the folded form. The structure of wool may be summarized as follows: 1. Amino acids are condensed to form long polypeptide chain. 2. The side groups of amino acids project from these main skeleton chains. lO _ m m m M/nrwlqlfiS n u . n W m m . m m H mm; H n u 3. H W m w m helmlmho a-IE—OO—GEB I! / 033-00-” I m no—n— 00-? E 1° 1------------—-- Miami/m m\mwmu._n|nm..nlm at u n n” H “in” d w n n n n e m n . . / .l .I II .|\0 . nave . mm " mnuwmnem ”mu . m/mlnlnlmq. sane” " V n ”ma. H u k u as, m n w. n H u: .. u .1... n sssss . u a u ”f. in u n." n m n m... u u n u m. n n m 3 n u I " mM‘r " " Paints... " a are... a..- wam " m\ m/m " m. u m\ .34 . a . . n H mm a e an; m a. n n We " n wsminrntm mlnbnlmlmrmlm Q )0 ll — —.s—8 .— _— m aggstine linkage 03" “Hz-“32"“ °9 /GB is O m 00 f“ 00 glutanic _arg ine of __ its“ jam-3204207: 63“ ,cm in BE . )0 “$3 00 gm cg -— — 8 ——8 —nzc GRAD lain cystine \ 3:0 06“ a i; _ \ RH . “g: - 09;“ ciflaanarogc acid mil-ya (3-820-320-ch f (SO/n:H - ‘ m as €° so co” 0 . cystine ' g): -- 632-— s —s —— Gar—“E“ 9° °8 DIAGRAM II Ast‘miry'a stretched form of 1001 5. 4. 5. An 12 Some side groups are polar and can attract water molecules, salts, acids, bases. These groups may be acidic or basic. Some side groups are non-polar. These are hydrocarbon chains which are water repellent. Adjacent chains may be cross linked by a) hydrogen bonding b) salt linkages c) cystine linkages. attempt has been made byConsder7 to illustrate these points in diagram on the next page. The zig-zag line has been used to indi- cate the side groups as well as the main chain; in this particular case it is assumed that each individual corner of a zig-zag is occupied by a CH2 group except where otherwise indicated. This is only a simpli- fied picture; the structure must be considered as consisting of a net- work of chains in three dimensions. ‘\ co . HN \ NH CO \ / c C HYDROGEN / \ BONDS \ ’ ACID'C — BASIC+ NH, 00C 0” 1 - HYDROXYL . AM'DE . HZNOC HYDROCARBON ’ < .‘/ I I I Al CH, / \ CH3 CH.S.S.CH ./ C ‘ISTINE CROSS LINK l4 LINKAGES IN WOOL It is found that there are four kinds of linkages in wool. First, the linkages between condensed amino acids in the long polypeptide chains. These are very strong primary valence linkages which require a considerable force to rupture them. The remaining three types of linkages have to do with holding the polypeptide chains together. These cross-linkages are the disul- fide linkage of the cystine in the molecule, the salt linkages, and hydrogen bonding. The Salt linkage: Since wool contains diamino acids (lysine, arginine) and dicarboxylic acids (aspartic and glutamic), the main pep- tide chains must carry acidic and basic side chains. The basic side chain of one peptide chain may combine with acid side chains from an adjacent peptide chain to form a salt comparable with an ammonium salt. After such a salt-forming reaction has taken place, the basic side chain of one chain would be like a positive ion, and the acidic side chain of the adjacent chain would be like a negative ion. These two ions would be held together by a strong electrovalent bond, thus forms ing a sturdy cross-linkage between two parallel chains. Such a linkage would be very resistant to physical forces which might tend to break it. However, since this linkage is the salt of a weak base and a weak acid, it would be susceptible to hydrolytic attack by dilute alkalies or even hot water. l5 Speaksmanl8’2l has presented evidence which shows that free basic and acidic side chains in wool are equivalent to each other, and he claims that the existence of neither free basic nor acidic side chains can be demonstrated. This means that the combined amounts of lysine, arginine and histidine is equivalent to the combined amounts of aspartic and glutamic acid, and that they are located in the wool mole- cule in such positions that their side chains can neutralize each other. These acids contribute about 25% of wool. It is apparent that the salt cross-linkages will contribute to the longitudinal strength of wool fiber. They also exert a certain amount of resistance to the stretching of the fiber. If wool is sub- jected to any condition or treatment that will break salt linkages, it will stretch more easily and show a decreased tenacity. The Cystine linkage: Since cystine is a diamino-dicarboxylic acid, there is a fundamental probability that it forms linkages between adjacent peptide chains. These linkages contain covalent bonds and therefore, contribute to the strength of the wool fiber. Not only do cystine linkages play an important part in the longitudinal strength of wool fiber but they constitute a significant limiting factor in the elongation of wool. Therefore any treatment which brings about the rupture of these covalent cross-linking bonds will contribute to the degradation of wool. The action of alkalies and reducing agents will cause such damage. Nillsenls’la claims that the cystine linkages of wool are respons- ible for its resistance dissolution as compared with other related animal fibers. 16 CHEMICAL PROPERTIES OF‘WOOL Reaction of W001 with Water Although wool is insoluble in water, yet it undergoes some changes when treated with water under proper conditions. There are three types of such changes: a) change due to physical causes, b) change in physical properties caused by chemical reaction, c) purely chemical change. When'wool is agitated in hot water, it felts and shrinks. This is purely physical reaction in which the epidermal scales of wool take part. Furthermore, wool loses some strength and stretches more easily when wet and still more easily if immersed in hot water. If wool is steamed and then stretched and held until cool it will retain the stretched form for a considerable length of time. The salt linkages of wool are those of weak acids and bases, and therefore they are hydrolysed by water, and the extent of hydrolysis will increase with temperature. Since salt linkages give strength to wool fiber and resistance against stretching, the hydrolysis and conse- quent rupture of these linkages will weaken the fiber. If wool is cooled and dried after hot hydrolysis of salt linkages, new linkages will be formed in quite different positions and thus aid in retaining the new shape. This change in physical properties is caused by chemi- cal reaction, i.e., hydrolysis of salt linkages. 17 If wool is heated with water at l50o C. under pressure, it dissolves. This is due to the hydrolysis of the main peptide chains, resulting in a mixture of amino acids, and the wool can no longer exist in fibrous form. Actions of Acids on Wool (a) Dilute Acids: Wool will absorb such acids as HCl, H2804, mics and chromic acid, and the absorption of these acids is such that a cer- tain amount of the absorbed acids cannot be rinsed off. This is prob- ably due to the acid combining with free NHZ group. The action of an acid, such as HCl on the salt linkage of wool is that of a strong acid on the salt of a weak acid to liberate the weak acid. It is represented as follows: 0' _ Q - R-COO + HsN-R-i- HCl—5 R-COOH+ R-I‘IHzCl (b) Concentrated Acids: Concentrated H2304 causes wool to swell, gelatinize, become rubbery and finally completely destroyed. Concen- trated HCl does the same thing over a somewhat longer time. Concen- trated EROS forms xanthroproteic acid, a yellow colored substance. (c) Organic Acids: The action of organic acids on wool is similar to that of dilute mineral acids, that is, they are absorbed from dilute solutions. Action of Oxidizing Agents on W001 Harrislo’llslsal7 made an extensive study of the action of oxidiz- ing agents, such as chlorine and peroxides, on wool. A weak oxidizing agent may not damage wool, but it does increase the sensitiveness of 18 wool towards alkalies. A vigorous oxidizing agent may damage the wool badly by attacking its cystine linkages. W-Chz-S-S-CH2-W 4-oxidizing agent-——A) ZW—CEZ-SOSH Then these linkages are broken, the wool becomes more stretchable and will break more easily. Action of Reducing Agents on Wool Reducing agents, such as sodium hydrosulfite and thioglycollic acid, will attack the cystine linkages of wool. This is illustrated by the action of thioglycollic acid. l’J—CHZ-S-S-Chg-w-i- 2hSCHZCOOH—m—s zw-CHZ-SH-a- (S'CHg-COOH)2 When the cystine linkages are broken in this manner wool becomes more stretchable and much weaker. Effect of Alkalies on Wool One of the most characteristic chemical properties of wool is the ease with which it is degraded in caustic alkali solutions. However, mild alkalies such as sodium.bicarbonate and sodium.carbonate do not harm.wool, if used properly. Ammonia is a very mild alkali and hence does not affect wool even at the boiling point for some time. Sodium.hydroxide can affect wool in three ways, it can break the cystine linkages, the salt linkages, and the amide bonds of the main polypeptide chains of wool. If wool is boiled with dilute sodium hy- droxide it is dissolved in a few minutes, due to the complete alkaline hydrolysis of the protein. When wool is treated with sodium hydroxide under milder conditions, the cystine linkages are easily attacked and ruptured, forndng sulihydryl and sulfenic acids. The latter react with NaOH to form.the sodium salt, which decomposes into an aldehyde and soluble sulfide. T -, - i - W-CHZ-S-S-CHZ-lv’d- HOB “11:13.1, VH-Cli2-8n+ W-CllZ-S-Oha W-CI-Ig-S-‘Na EL) WCHO -+ ’ Nags + HOE At the same time salt linkages are ruptured, as shown by w- coo“ + HEB-W + NaO H -—)w- c0633; 4- VJ-NHZ +HOH Wool loses strength when treated with NaoH. The loss increases with the increase in concentration of NaOH until it reaches 23%, after which wool becomes stronger, whiter, has a higher luster and silky scroop. The change in strength with variation in NaOH concentration wnl4 is sho in Table 2. EFM‘JU'J' OF ALKALI 01'! S‘."};'I.ITC'II1' 0E" I'JUCIL E‘CE’; w-- .-»-o O O % NaOH {1.1).} LT! l I 20 ”1,.-i _ q , lo q ELVL LiitTLb A? 10 t. Breaking Strength % Change in Strength Grams 0 610 3.0 510 - 16.4 5.5 475 - 22.1 8.0 250 - 59.0 11.0 180 - 70.5 15.0 95 - 84.5 18.0 200 - 57.2 22.0 240 - 60.6 30.0 580 - 4.9 35.0 770 + 26.2 58.0 815 ~1- 33.6 BUILDING OF NEW CROSS-LINKAGES It has already been shown that wool is very sensitive to alkalies, reducing and oxidizing agents, and that this is associated with the cross-linkages. Therefore efforts have been made to stabilize wool by forming new cross-linkages which are more resistant than those in native wool. Much of this work has been done by Speaksman in.England ' and Harris in the United States. 1 Speaksman 9 bases his work in the well known reaction between pri- mary amines and formaldehyde. - £1 , Is R-l-IHZ-lv- ('3 Z O + IizN-R -~) R-Ifli-(E-NH-R 4- H20 11 H He assumes that free NH2 groups in parallel peptide chains will react with formaldehyde as shown in the following equation: ,A. H ! W-CH 41112 - ‘-'- 0 +H21‘I-CI'12—W ——)W-CH2-I‘GH-C-NH-CHZ-W +H20 2 m—o-tr: It is seen that a new cross-linking has been formed, containing co- valent bonds and a CH2 group. Harris9 and co-workers have worked on the cystine linkage of wool, splitting it by the action of reducing agents, followed by the intro- duction of a neW'cross—linkages between the sulfur atoms. This is shown below where thioglycollic acid is used as the reducing agent and ethylene dibromide as the cross-linking agent. W-CHZ-S-S-CHZ-W-+-2HS-CH2-COOH-—-4)ZW-CHZSH - (SCHZCOOH)2 Zi'ul-CHZ-SH + Br-CthHZ-Br ———:, w-CHZ-s-CHZ-cag -s-CH2 -w 22 It is seen that the alkali sensative disulfide linkage no longer exists, and that there are now two carbons between the sulfur atoms. The fib— rous structure of wool is not affected during this treatment. Brown and Harris12 have reported an improved method of stabilizing the cross-linkage in wool by immersing the wool in a bath containing both the reducin agent and the cross-linking agent. Sodium sulfoxy— late formaldehyde, NaHSOZ-CHZO-ZHZO (or corresponding zinc cegpound), or sodium.bydrosulfite Na28304, ZHZO, thiomethyl urea, Chgflh-g-NHZ or formamidine sulfinic acid NH2-§;SOZH may be used as reducing agents, ‘ I and compounds for rebuilding are dihalides. In this method, as soon as a disulfide linkage is broken to form sulfhydryls, the cross-linking reagent acts immediately to form a new and more stable cross-link. This process of the formation of new and more stable cross-linkages is very useful in the wool shoddy industry. Chemically this stabilized wool has many advantages over native wool, most important of which are its increased resistance to the action of caustic alkalies and reduc- ing agents; it is also resistant to attack by moths. X-ray study of fiber was made by Sponsler22 and Doré'in 1926, May and Mark in 1928, and explained the structure of fiber. It explained the chemical behavior, physical properties as well as its X-ray data. When the component parts of a substance are oriented or arranged in some definite form, the substance is considered to be crystalline, whereas if the parts are irregularly and heterogeneously placed, it is known as an amorphous substance. X-ray analysis of such crystalline substances show a definite pattern, and all samples of a particular substance show the same pattern. Thus crystalline subseances show a definite crystal lattice. Amorphous substances exhibit no such lattice. 22'4 and Mark in 1928 found that protein fibers orient in I»: e ye I‘ crystalline form. They measured distances, the length of repeated units in the pattern. They analyzed stretched fiber and found that the pattern was quite different. Thus they established the presence of crystalline and non-crystalline components of the fiber. 24 E XPER I 1er EJTAL Apparatus: The apparatus consisted of two 2~liter graduated glass cylinders; one contained distilled water and the other contained the solution for testing wool; the latter was provided with a vertical scale attached to the back of it. The distilled water cylinder was kept at room temperature, but the cylinder containing the test solu- tion was placed in a constant temperature water bath. The temperature of this bath was adjusted for two complete series of experiments, one at 29.80 c. and the other at 39° c. A 10-inch piece of wool yarn. was fastened rigidly at the top with a clamp that could be raised or lowered so as to immerse the proper length of yarn in the test solution. The bottom end of the yarn was provided with a weight (hereafter called the stretching load). The weights of these stretching loads were 18, 42, 72, 97, 125, 153 and 185 grams. These weights were made of glass. The wool used was 4-fold white "Botany" knitting worsted, manu- factured by the Botany'Worsted Mills. Chemicals: Chemically pure sodium.hydroxide was used for the test solutions, and it was made to be 0.1N, 0.2N, 0.3N, 0.4N, 0.5N, 0.75N and 1.0N solutions. The solutions were made to exact normali- ties by standardizing against a standard solution of hydrochloric acid which previously had been standardized against a stand solution of sodium.carbonate. Chemically pure sodium.carbonate was used. 25 Thioglycolic, HSCHZ-COOH, acid was used for testing the stretch behavior of wool when exposed to the action of reducing agents. The thioglycolic acid was the Eastman (practical). It was made up of con- centrations of 0.1K, 0.2N, 0.5N, 0.4N and 0.5N (equivalent weight 3 92.11 grams). Procedure: Wool yarn was fastened rigidly at the top with a clamp which could be raised or lowered, and provided with a weight on the lower end. It was then suspended in distilled water for five minutes.- This permitted the yarn to adjust its length to plain water by removing kinks and allowing for any untwisting of the yarn. During this time the length of the yarn from the point of suspension to the point where the weight was attached, was adjusted so that exactly ten inches of wet yarn were submerged. After the five-minute immersion in distilled water, the yarn was transferred to the alkaline test solution, and a scale reading was taken at once. This zero time reading was taken where the lower end of the yarn cut the scale attached to the glass cylinder. A second reading was taken after one minute so that the zero reading might be checked. The time intervals between subse- quent readings were varied. It was found that the length of the yarn changed very slowly in the more dilute NaOH solutions (0.1N and 0.2N) and readings after fifteen minute intervals were satisfactory. However when yarn was immersed in 0.3N NaOH, it was necessary to take readings after five minutes, and when 0.5M and 0.75N NaOH solutions were used, the time interval was reduced to one minute, and after fifteen such readings, it was out to one—half minute. 26 The exact time of each reading was recorded. The differences be- tween the zero reading and all subsequent readings are the changes in length of the yarn after the recorded periods of time. These were converted into percent change by dividing the change in length by the total original length of the yarn. In some cases the first thing noted was a contraction of the yarn (a negative change in length), after which the yarn began to stretch. This phenomenon of contraction was found to depend upon the concentration of NaOH solution and the stretching load used. 27 RESULTS Contraction: The behavior of wool yarn, when immersed in solutions of NaGH of varying normalities, is peculiar. The first thing that happens is an unexpected contraction rather than a stretching. In gen- eral, the amount of contraction of the yarn depends upon the following factors: (a) stretching load (b) concentration of NaOH solution (0) temperature of NaOH solution. (a) Since a stretching load would work against any contraction brought about by either physical or chemical means, it would be ex- pected that the observed initial contraction would decrease as the load is increased. This is shown in Graph 1, where the maximum con- traction is plotted against the stretching load for 0.5N NaOH at 29.80 C. It is seen that wool shrinks about 3.27; in 0.5N NaOH at 29.80 c. when the stretching load is only 18 grams. As the stretching load is increased the amount of shrinkage is less and less until, with a weight of about 140 grams, no contraction is observed. The curve shown in Graph 1 is typical of the behavior of wool yarn when immersed in kute solutions of NaOH. This curve was plotted from laboratory measurements using different stretching loads. The figures for four such loads are shown in Table III. These are typical examples; other loads gave similar results. 28 mxwoam mm.m¢ oaum 0m mm.0¢ 0H|m mm 00.m Huea 00H ms.m¢ mum 0w mxsoam 00.m HIwH 09H om.m¢ sum 0» 00.0m Nana HNH 00.m lea mwa 00.0w 010 00 msonm Hana QNH msm.¢ onwa oma Hw.m| manma 0NH ms.mm 010 me 00.0w mum moa msm.¢ 0|¢H om Hw.xl malma om mm.am «Hum 0w 00.5w 010 00 ms.w manna ms Hw.m| malma ms 0m.sm Hanw mm 00.mm elm ms ms.m manna 00 Hw.mu manma 00 ms.mm mum on mm.am Him 00 mma.m| eanma me om.m| wanma me 0m.sa mum mm mm.0H manw we msm.al NHIMH 0w 00.m| ealma 0m ms.w mans 0N ms.w sum 0m mm.al puma ma mm.a| manna 0m om.m sis ma 00.0 mans ma mmm. I wlna m mm.al oorma ma 00.0 «In N 00.0 male m 00.0 mind m 00.0 0mrma m 00.0 ets 0.0 00.0 mans 0.0 00.0 mlma 0.0 00.0 omlma 0.0 emsego wcw osHE ewsego mam .nflE omasgo wsw .SHE emneno wnfl .mflE ”a uooox 2:3 “a loom! as: ”a. .361 an; a -eoom o5: madam me mEehw mma madam ms mssaw 0H 0 00.0m mosz Zn.0 HHH mamde 50 (b) Dilute solution of NaOH such as 0.1N show very little con- traction, but as the concentration is increased, the contraction becomes significant. However, it reaches a maximum beyond which it begins to decrease. This is shown in Graph 2 where concentration of K803 solution is plotted against percent contraction obtained with 18 gram load. It is seen that the maximum contraction (when an 18 gram load is used) occurs in an NaOd solution of about O.bN at 29.80 C., and about 0.3N at 39° c. The same thing was observed with great— er loads, that is, the maximum contraction, even though it was smaller, occurred in these same concentrations of NaOH. (c) Higher temperature seems to decrease the contraction. This is shown in Graph 2 where percent contraction is plotted against normalities of NaOH for two temperatures, 29.80 c. and 39.00 c. The maximum.contraction at 39.00 c. is 0.75% and at 29.80 c. is 3.25%. It was found that, with an 18 gram load there was no contraction in 0.75N NaOH at 39° 0., whereas at 29.8° c. this did not occur until 1.0N NaOH was used. The same relative difference was noted when greater loads were used, even though the actual contractions were smaller. It would appear that the higher temperature favors those factors which are connected with stretching rather than shrinking. 4 . .<.. 4 4 M 1 14‘ . i A. A 14 i J] A. . J . . _ . . . . . . a . . v ‘ . . A r . . _ v . . r . . y n t . q . . — a . . o . . . u . . . . A . . . a r . u a . s . . . . _ . ._ v . . P . s v t * c . , o . a . A .A. e . . . . . . o . ~ . I . . a . A . > . . v . . . . . . . . e . y . . o o, . . . . . w. . _.. . . . . 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Ill Il'holl'.1 } W, iii IIIILIOII III. _ , ;”.:. Uni..: . Mg. 1, J. _- .in. . .3, ,H , .2. . . . .._. . g . H ...HLH. .w , . .. .. _l ... ._- Jr- . f._ *4. .—.o—~4 ‘ l QOIL .91. . ritszolv-‘ .Juo‘ ‘5‘}. :317'IOATVHII» 7‘. .....° 1 n --- . _ 3 i +- .- __ _.. a .4 - -.._. Ir ~——’4y—+--- . .‘Ink I’ll!" I i To .vlrl .‘a—.-4L. "_..4 . l ‘*‘+"‘f“i"i' ”rs—wfir 9 I L r ;_._.,_ I § 4..-; --§.._. .‘_._‘ —_-.. - Loa< F- .4 .—4 --_ - >-- . i - -.4,_._.. ._. - _- _r .f a. i. ii 0mm. 2 l . ._ n g _ .r 4 _ ... . . . I .A . .¢. . . . . ... t q . . .. . _ . .o . 6 o . , a . . u .. tn. ~ . . .. “*V .. . . a v. ~ . . ._ . .. M . o c . . o . _ . . . .n . .. ..o . . M . . . . a .. . _ . .. ... .. . A .. .. . . . . u . .. . . . . . .. wolf? r rt ‘11 i .r ol‘InIlLvQIIQ-4 _ .4... . .. ... .. . . .. ..-c t?. . .. . ., .. o. .. . . . ..«. . .1 . . .. .. . . 4 .. .o... . .. . .4. . . . . .. . . .. . 1v.-_... . . . _. ... . .4. .. . . . .. . . ... .h. e a e .+...~ 7. k .. . .. . u 7. 1V . 0v. . ._ . .. .l. . . y. *. .. . . _ . 4 . " .0?..b. . u ...Lr A .L. ..y. .. _ .... ..o .o .1. .o . ... . v. . ..k._ . m . v . r H '7 22.5: «.53 x Stretching of Wool in Solutions of Sodium.Eydroxide When wool yarn is immersed in solutions of sodium.hydroxide, after an initial contraction, if there is any, it begins to stretch. The present investigation has to do with a study of the extent of this stretch, the time involved and the point at which the yarn breaks, as related to such factors as temperature, concentration of NaOH solutions, and the stretching load on the yarn. Two temperatures were used in this study; 29.80 C., hereafter known as the lower temperature, and 39.00 C., hereafter known as the higher temperature. All stretching effects were greater at the higher temperature. Results obtained at lower temperature are discussed first. The Lower Temperature (29.80 C.) No stretch was observed in solution of 0.1N KaOH even with a load as great as 185 grams, up to 180 minutes. No stretch in 0.2N NaOH was observed until a load of 97 grams was applied and even with such a load the stretch after 180 minutes was only 1.25%. In 0.3N NaOH no stretch was observed until a load of 72 grams was applied and stretch observed with this load after three hours was 1.8%. 'With a load of 153 grams the maximum stretch was 55.0% and the yarn broke after 121 minutes with this load and after 95 minutes with a load of 185 grams. The results obtained with 0.5N NaOH are shown in Table III and are plotted graphically on Graphs 3, 4, 5 and 6. It is seen that only with loads of 153 grams or greater did the yarn break, even up to a three hour immersion. 53 When wool yarn was suspended in 0.4 N NaOH it stretched much more easily, and even with a load as small as 18 grams it stretched 3.12% in three hours. The yarn also broke more easily in 0.4N NaOH. 'With a load of 42 grams it broke after 115 minutes, and with a load of 185 grams in 16 minutes. The results obtained with 0.4N NaOH are shown in Table IV and plotted in Graphs 7, 8, 9 and 10. It is seen that a much smaller load is required to break wool yarn in 0.4N NaOH than in 0.3N NaOH. It was found that 153 gram.load broke the yarn in 0.3N NaOH, whereas only a 42 gram load broke it in 0.4N NaOH. Thus the stretch of wool yarn in NaOH solution increases as the load and concentration of NaOH increases, and the time taken for the yarn to break decreases. The Higher Temperature (39° c.) No stretch was observed in 0.1N NaOH even with a load as great as 185 grams up to three hours. No stretch in 0.2M NaOH was observed until a load of 72 grams was applied and even with such a load the stretch after 180 minutes was only 1.75%. The maximum.stretch was 18.0% after 180 minutes with a load of 153 grams, but the yarn did not break. These results are shown in Graph 11. In 0.3N NaOH considerable stretch was observed even with a small load of 18 grams where it stretched 1.88% after 180 minutes. The yarn started breaking after 115 minutes with a load of 42 grams but took ma.m mlma Ova ma.m ulna mwa 0m.m mIma 0ma 0m.m mIna nma .oem masonm nmImm msw.a wIma oma 00.am waIaa mm mm.a wIma moa em.mm wIaa em mmw. mIma 0m 00.mm nIaa mm 00.0 aIwa ms mm.am. sauce on 00.0 Hume oe .oem .eom maeoam malma madman amnom ma.wa wuoa mm mmw. 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V..V%..V.HHVJV .V.:V V. ..VVirVVVLVVVVVVVVVVVVVVVVV VVVV . 7 4V; {V V V V VVV V ‘ - [I V V ..V V. .H . V .V Viv! .Vrtv .. V .VV ... VVV V. .V V V .V V .V VVV .V V VH V . V. V V: H V. ..1. .V. V-:» V .V. V V. V V . VVVVVH... V.:V VVVV _ . V . ... V. V.. . . V “V .V .... . V .M V H . . V .H. . H.... V.. ..V . . _ . .4 .V V. . V ... H _V .. w . V b 4 o V. V .V H V .V V VV V 4 V V. .VV V .V .V V VVV. V... V, .H V, V V 11111.; :tértszV V . V :. VVV VVVV V.. . V, V VV V, V VVVV . VHV V.V: ”up .. V V ..V .VV V :V. 9.1.»! in}: .iVVVVVV!-VV--l»erLVTIVV- V V. V” V V 9V V V... ..VV.V ... . V. 611$ V V V V V ... .. H V V. V1 V 8. 4V. .tVVVwVVVfVVVV VMVJVV-1-V--V1JTIV.1 VV. V . V V V. ._.. V V V. H V ..VV V. V V V .V. V V V V V:.. VV.VV. .. VV VVV V V ”V V V .V V V V VVV . . VV V 8. .fl... V 1.. t . . V V . . A V w .. .V. V¢~. . Lfi:1+t V V V .HVVV V. V. . V :V V V. V V. V VV V V V . Vi. .Vx V . é : . V. Ll 13.111! ttlLrvtrL. .. V. V .. s . . VV. . . V V V .V . ...H V V 1111-»- i V- ? . . V . . . 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W... V H... u.. 4 ... V. ..4 Lfi .0 VVu..V:T ... .VV.:.. V . . IV: 2 V ..V ....V maozuq 2H H. O ZSVH o mam:zaomam 43 only 15 minutes to break when stretched under a load of 155 grams. Results Obtained with 0.3N NaOH are shown in Table V and are plotted in graph form in Graphs 12 and 13. 44 mxwoum mHH .oom wxdohm ma mxdopm Omnmw 00.0H wflsma OHH m>.mm mauoa ma mmoam mum mw msm.m manna moH msm.a wlma owH mu.mm HHIOH ea oo.mm manw ow m.> Gamma Om mmoa sun Qua omoum mica ma mm.Hm calm mm mm.m wnma we mmwoon muma oea om.mm NIOH NH msowa mum on oo.m wlma ow 00.0 mind omH omosa «Hum Ha mmooa mum mm mma.m mama m¢ www.01 Nina om m>.ma Halo OH ow.ma mum om mmm.ou mHINH om mm.au muma om mu.m bum m ms.w ouw ma 00.0 walma ma mm.Hu mnwa ow com «um m ms.m mans OH www.01 manma 0H msm.H| mind on m.m mum m 00.0 mus m mm.H| NHINH m msw.H| mlma mm mm.H Hum m mmooon was m mmw.0| mauma m m.m| Huma ma as 8% 3238 H 8.0 mus H 8.0 3an H 8.0 9.2 m 00.0 cum 0 00.0 one o 00.0 wHINH o 00.0 mlma o mwcwxo mu“ .QHE owmdgo we. .qfiz mumsno wmw .mflz owcago wnfi .QHE ma Ilauwgm we: we“ 4.30m as: x .35m as: m -33 as: mEdhw a“; 28% um madam mw Enduw ma .0 can momz 2woo > m4m- .m. . ~. A. A .4 4 .A. 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M A A M J -4. . .- .. 4 . - . . _ t . r A: A A A AA .A AA A a. g. A l l AA;A_AAAA A A ... A. . . A“ w n 4 . -.u.*.. ~ . _r .f .. ..A ts. ... A A A .A _. A A A .- Ar. .. A... . A _ - . - < n .X Li.) A ..A ._ A... 3. —. 1 . .__ .m»... .:..CH A— 0‘. 48 In 0.4N NaGH solution, a stretch of 14.0fliwas observed even with a load of 18 grams and the yarn broke after 53 minutes. The yarn broke in 12 minutes with a load of 97 grams and showed a maximum.stretch of 47.5%. The results obtained with 0.4N NaOH are shown in Table VI and are plotted in Graph 14. Therefore, it was observed that the stretch of the yarn increases in NaOH as the load and concentration of NaOH increases, and the time taken for the yarn to break decreases. It was also noticed that the stretch for the same concentration of NaOH, with the sane load, was greater at higher temperature. The time taken for the same stretch is less at a higher temperature, provided the load and concentration of the solution are the same. In experiments in which the yarn broke it was quite difficult to determine the percent stretch at the breaking point, and the time re- quired for the yarn to break. However, in all such cases the same phenomenon was observed, that is, the yarn would start stretching and continue to do so until suddenly the rate of stretching would increase rapidly, and after a short time the yarn would be completely broken. It was thought that the percentage of stretch, which might be pertinent to any conclusions, should be taken as the amount of stretch at the time of the rapid increase. The same decision was made with regard to the time required for breaking, that is, the difference in time between when the rapid increase in stretch started and when the yarn finally broke into two parts, was so small as to be negligible. mowz 2¢.O H> MAMdB exeoam mm .oew mxdeam mlee mmH.mH OHIeH Om madcnm mumH om.>m mum ow www.0H muwH we om.s¢ wnoH om NH mm.mm mum mm manom enea oe oo.mw mnoa NH exeeam 5H om.mm mum on mmH.w mneH mm oo.mm waum HH ms.mm mica ma oo.om cum on mam.o oaeH on m5.wm mum 0H mb.mm Hana NH mm.oH malw mm mmm.m wanna mm om.mm elm m mb.mm elm 0H om.ma oalw om mma.» oalma om as.nH mHum m om.s oanw w omom mum OH mm.H| hImH mH om.e mum u mm.H mum m 00.0 01w m om.m| HInH m 00.0 mum m 00.0 elm m mm.H| mane n mm.H| mIeH m mme .0 Hum H as .o.. mane H 8.0 one H 8.0..- a-» H 00.0 mum o 00.0 film 0 00.0 cum 0 00.0 mImH o owqwxo wzfi .:fl: ownego wad .aflz ewseno wad .aflz ownego we“ .:fiE m“ I, ueeom eEHH mm .Iiluwmwm mafia R nueem QEHB R neeem mafia madam em mEeaw ms madam me afieaw ma .0 can ‘ I.“ lulll:|u .. III | 1“ lg”l it ‘ 51 A specific example will illustrate the above. In 0.4N NaOH at 59°C. with a load of 42 grams there was a small contraction during the first few minutes, and then after about six minutes the yarn started to stretch. It continued to stretch at a fairly slow rate for 40 min- utes, at which time it had stretched 25%. At this point it started to stretch very rapidly and in the next 30 seconds had stretched to 42.5% and was definitely broken. It makes little difference whether the time for breaking is taken as 40 minutes or 40.5 minutes. As far as the amount of stretch at the breaking point is concerned, the rapid additional stretch of 17.5% was considered tolne associated with the actual breaking of the yarn, rather than with stretching. In this ex- periment, herefore, the stretch at the break was taken as 25%. These exoeriments have shown that, other conditions being equal, an increase on stretching load makes the yarn stretch more and causes it to break in a shorter time. This would be the expected behavior of wool yarn when exposed to the action of alkali. The laboratory results will now be arranged in such a way as to show the quantitative effect of stretching load on these two things. That is, the results will be presented so as to show whether or not the increase in the rate of stretching keeps pace with the change in time for breaking. On Graph 15 stretching load is plotted against the time required for breaking at 29.80 C. The quantitative effect of load on the amount of stretch in wool yarn is shown on Graph 16, where load is plotted against percent stretch at the breaking point. These relationships are shown for three concentrations of NaOH. 52 Graphs l7 and 13 show the same things except that the curves have been plotted from figures obtained at 390C. The conclusions that can be drawn from these four graphs will be given in the section on the discussion of results. .- ‘0 1 I I o O 0 8 tr: Cu C~ s. C— n}! ’131‘ I‘ka I JI‘,‘I\ mo 57 Action of Sodium Carbonate and Sodium Hydrosulfite on hool Yarn These two compounds are used in the processing and reclaiming of wOol and it was thought that it would be interesting to determine their effect on stretch and contraction of the wool yarn. Standard solutions of 0.1H, 0.2N, 0.3N, 0.4N, 0.5H, 0.75N and 1.0N Na2003 were prepared and wool yarn was suspended in them at 29.80 C. and 59° C. for 180 minutes. No stretch of wool yarn was noticed even in 1.0N Na2005 solution for 180 minutes with a load of 190 grams. Standard solutions of sodium hydrosulfite (Na28204, maze) of 0.1N, 0.2N, 0.3N, 0.4N, 0.5N, 0.75N and 1.0N were prepared. Wool yarn was suspended in these solutions at 29.80 c. and 39° c. for 180 minutes. No stretch was noticed even in 1.0N solution with a load of 190 grams for 180 minutes. 58 W001 and Thioglptollic Acid Thioglycollic acid, HS-CHZCOOH, has been used as a reducing agent for splitting the cystine linkage of wool after which the wool may be treated with a cross-linking compound, such as ethylene dibromide, to form new and more stable cross-linkages. In order to determine the contractile and stretching properties of wool when treated with thic- glycollic acid, the following experiments were carried out. Chemically pure Eastman Kodak Company thioglycollic acid was used and prepared approximately 0.1H, 0.2N, 0.5N, 0.4N, 0.5N and 0.75N solu- tions by dissolving 18.4, 56.8, 55.2, 73.6, 92.0 and 138.0 grams and making up to 2000 milliliter solution with water. The solutions were titrated against standard KMn04 to find the exact normalities of the solutions. The same apparatus was used as in the NaOH experiments and the experiments were carried out in a similar fashion. However, only two loads were used, 150 grams and 190 grams because with lower weights the change was not measureable. No contraction was observed at lower or higher temperature, with either heavy or low weight used. Stretch at 29.80 C. (lower temperature) No stretch in 0.1N thioglyoollic acid was observed until a load of 190 grams was applied and even with such a load, the stretch was only 1.25% after 60 minutes. This did not change although the yarn was kept suspended in this solution for 180 minutes. 59 The maximum.stretch obtained in 0.4M thioglycollic acid solution with 190 gram load was 4.37% after three hours. Table VII shows the results obtained in 0.4M SH-CH 0005 solution with 190 gram load which 2 are plotted in Graph 19. 6O TABLE VII NORKALITY'OP THIOGLYCOLLIC ACID = 0.4N Leia : 190 GRAL'ZS TEMPERATURE : 29 .80 C. Time in Minutes Reading Stretch in Inches Percent Stretch 0 12-15 0.00 0.00 5 12-15 0.00 0.00 20 12-14 .0625 .625 45 12-15 .125 1.25 60 12-15 .125 1.25 100 15-0 .1875 1.87 120 15-1 .250 2.50 150 15-2 .5125 5.12 180 15-4 .4575 4.57 .‘r.l§‘!‘l' .1 "I'l 62 Stretch at 59.00 C. (higher temperature) The stretch of the wool yarn increased when it was immersed at higher temperature, showing a stretch of 1.87% even in 0.1N thiogly- collic acid with a load of 150 grams after three hours. As the concentration of thioglycollic acid was increased, the stretch increased so much that in 0.5M solution with 150 gram load, the stretch after three hours was 50.5%. The results obtained with a 150 gram load are plotted on Graph 20. As the load was increased, more stretch was noticed, so much so that with 190 grams in 0.5N thioglycollic acid solution, the stretch was 58.75% and in 0.75M thioglycollic acid solution, the stretch was 61.25% after 180 minutes. But the yarn did not break even after three hours. Table VIII shows the results obtained in 0.4N thioglycollic acid solution with a load of 190 grams at 59° C. The curve for these figures is found on Graph 21. 5.55 8.. s 0 «teens. so .lllllll" 1" TABLE VIII NORHALITY'OF THIOGLYCOLLIC ACID 3 0.4N LOAD : 190 cam-as it‘mammm : 39.0%. Time in Minutes Reading Stretch in Inches Percent Stretch 0 15-0 0.00 0.00 5 15-0 0.00 0.00 15 15-1 .0625 .62 50 15-5 .1875 1.87 45 15—4 .250 2.50 60 15-7 .4575 4.57 75 15-12 .750 7.50 100 14-0 1.00 10.00 120 14-5 1.5125 15.25 155 14-12 1.75 17.50 150 15-0 2.00 20.00 180 16—2 5.125 51.25 5 . . 59min no ..u. . «Enema» .1 .a 3:: 9.4.1 1 1'11! 4 {1l41|.‘| -l0 DISCUSSION OF RESULTS First we shall make a brief summary of the results obtained when wool yarn is treated with sodium hydroxide, sodium carbonate, sodium hydrosulfite and thioglycollic acid at two different temperatures. This will summarize such things as contraction, stretch and breakage as related to concentration, time, temperature, and stretching load. Contraction: (29.80 C.) There was no contraction in 0.1N NaOH. It started with 0.2N and increased until the maximum was reached with 0.5N NaOH, and then began to decrease as the concentration of NaOH was increased. The maximum was 5.25% in 0.5N NaOH, whereas it was only 2.5% in 0.7N KaOH and zero in 1.0N NaOd. As would be expected greater stretching loads should decrease the amount of contraction, but these loads were surprisingly large. For example, the following percentages of contraction were obtained in 0.5N NaOH with the indicated stretching loads: 5.25%‘With 18 gram.load 2 . 2 U 42 N H 0.7 I! 97 II II 0.0 H 140 H H Stretch: (29.80 c.) ‘The yarn did not stretch in 0.1M NaOH. In 0.2N NaOH there was some stretch, but not until a weight of 97 grams had been attached to the yarn, and then the maximum.was only 6.9% after 2 hours. 67 In 0.5K NaOH a load of 72 grams caused a stretch of 8% after two hours, and a load of 155 grams stretched the yarn 55% in two hours, after which it broke immediately. Break of Yarn: (29.80 C.) The yarn did not break in either 0.1M or 0.2N NaOH, even after three hours with a weight of 155 grams. In 0.5K NaOH it broke with 97 grams after two hours. In 0.7M NaOH it broke in 19 minutes with a load of only 18 grans. Contraction: (39° c.) At the higher temperature the maximum contraction was reached in more dilute solutions of NaOH, and in a shorter time, but the amount of the maximum.contraction was smaller than that obtained at the lower temperature. As before the maximum.increases with concentration up to a certain point and then decreases, as shown by the following contrac- tions obtained in the indicated solutions: 0.5% in 0.1N NaOH 2.75 ” 0.5 " 0.5 " 0.7 " The effect of stretching load is the predicted one as shown below. In 0.5N NaOH contraction was: 2.75% with 18 gram load 1.25 " 42 " " 0.6 " 97 ” " 0.0 140 n n Stretch: (59° C.) The yarn did not stretch in 0.1N NmGH even with 184 gram load. 68 In 0.2M NaOd stretch was observed more than at the lower tempera- ture and in 0.5K NaOH it stretched considerably more and actually broke after two hours with a weight of 42 grams. 'With a load of 97 grams it stretched 51% in 45 minutes and broke immediately afterwards. Break of Yarn: (59° c.) The yarn did not break in 0.1m or 0.2M NaOH. In 0.5T NaCH it broke in two hours with 42 gram load. In 0.4N NaOH it broke in 15 minutes with a 97 gram load. As would be expected the higher temperature brings about breakage of the yarn with smaller loads and in shorter time. Behavior of Wool Yarn in Sodium Carbonate There was no contraction, or stretch, or breakage of the yarn in solutions of Na2C03 up to 1.0N, even with a load of 190 grams for three hours at either temperature. Behavior of Wool Yarn in Sodium.Hydrosulfite There was neither contraction nor stretch in solutions of sodium hydrosulfite under the maximum conditions. Behavior of Wool Yarn in Thioglycollic Acid The yarn did not show any contraction in these solutions, nor did it break under any of the conditions employed, but there was consider- able stretch obsorved. This dtretching took place much more slowly than in alkaline solutions of NaOH, and required much greater loads. It was found that increasing the temperature from.29.8O C. to 590 C. 69 had much more effect on the stretch than was the case with solutions of NaOE. Typical figures obtained are as follows: In 0.41: acid (29.80 0.) 4:5 stretch with 19-0 grams in three hours :1 n n (390 C.‘ 30;; u n 190 n u n n In 0.7511 acid (390 C.) 61,5 :1 n 190 N n u u The Contractile Eehavior of tool It is well known that wool fibers will swell in aqueous solutions, and as they swell they must necessarily contract, unless such contrac- tion is prevented by a load working opposite to the contraction. Swell- ing in wool fibers is a physical change brought about by temporary and reversible chemical changes. It would be expected that such a physical change would reach a maximum, that is, the swelling of wool fibers should reach a maximum, above which it could not take place without destroying the reversibility of the chemical changes. It is important to remember this. Speakmanl8 has shown that the swelling of wool fibers (with the accompanying contraction) is a function of 0H ions. This will happen even in water, but the time required is very long. In the present ex- periments no contraction was noted in 0.1N NaOH at 29.80 C. up to three hours. If swelling of wool is a function of 0H ions, and if it is brought about by a chemical change involving such ions, it would be expected that more swelling would occur in 0.1N NaOH than in water, be- cause of the higher 0H ion concentration. It is assumed, however, that the time required would be longer than three hours, since no contrac- tion was observed in 0.1N NaOH up to three hours. In these experiments 70 the wool yarn was first immersed in distilled water, but under a weight. Thus at least part of the swelling action of water had already taken place before the yarn was put into the alkaline solutions. Increasing the concentration of NaOH means an increase of Oh ion concentration, and therefore more swelling should occur when wool is subjected to stronger NaOH solutions, and it should contract more. This appears to be true up to a certain point. Wool contracts more in 0.5N NaOH than it does in 0.2N, and still more in 0.4N and 0.5V NaOH. However, in 0.5m seen it seems to have reached its maximum (29.80 c.) and if it is immersed in 0.7N NaOH the contraction is less. This must be explained. he must now call attention to the fact that sodium.hydroxide acts upon wool in two ways, as a result of which opposite physical changes are evident. First, NaOH causes wool fibers to swell and shrink. Second, NaOH causes a rupture of the cystine linkages of wool, a break- ing of the salt linkages, and finally the hydrolytic cleavage of the main polypeptide chains of the wool protein. The first action of NaOH causes wool fibers to contract, whereas any of the second actions causes it to stretch. Apparently the former effect is the more rapid. For example, in 0.3N NaOH with a load of 18 grams the maximum contrac- tion is reached after about 50 minutes and there is no change in the length of the yarn even up to about three hours. That is, the second effects of NaOH have not become measureably operative in that length of time. However if a weight of 72 grams is used on wool yarn in 0.3N NaOH the maximum contraction (smaller than with 18 gram weight) is 71 reached in about 15 minutes, after which a reversal begins, and after 25 minutes the yarn shows definite stretching. As stronger solutions of NaOH are employed the time when stretch- ing starts becomes shorter and shorter. There are, then, two things working against each other-~tre swelling action of NaOH and the degrada- tion action of the alkali. The latter would obviously increase with an increase in concentration, and thus the swelling action is reduced or neutralized by increasing rate of degradation, until a concentration of NaOh is reached, in which no contraction is noticed. The effect of temperature on contraction is interesting. Since chemical reactions take place better at higher temperatures, it would be expected that swelling would take place more easily at higher temp— eratures and therefore contraction of wool yarn should be noticed with lower concentrations of alkali. This was found to be correct and is clearly shown in Graph 2. However the strange part was that the maxi- mum.contraction was reached in 0.3N NaOH at 390 C. instead of 0.5H. Furthermore, at 390 C. the contraction in 0.5N seen was less than in 0.3N. These facts are easily explained when we consider that the higher temperature enhances the splitting and hydrolytic effect of haflh much more than the swelling effect. Two more effects of temperature should be mentioned. They are the effect of temperature on the maximum.contraction as related to concen- tration, and the effect on the time required to reach such a maximum as related to concentration. To illustrate the first, the maximum contrac- tions for 0.5N and 0.7N NaOH will be given for the two temperatures. At N 29.80 C. in 0.5N NaOH maximum was 3 O o 511 " u H 2 o 72 ESA‘with 18 gram load rzc ’ n II II II L'l'G As we go from 0.53 to 0.7N KaOH the change in maximum is in the ratio of about 4 : 3. At 390 C. in 0.5N haOh maximum.was 1.95%‘with 18 gram load 1| " " 0.7K H I! I! 0.5;; b," H H I! H As we go from 0.5h to 0.7N haOH at the higher temperature the ratio of the two maxima is about 4 : 1. It is clearly seen that an increase of temperature causes a much larger drop in contraction as concentra- tion is increased. However, the effect of increase of temperature on the time re- quired to reach a maximum.contraction is almost negligible. The change from 0.3N to O.-H NaOH will illustrate this. In H This is In This is 0.5N haOH time is 50 minutes with 18 0.41M" " a ratio of 2.5 H H 20 II I! H :1. 0.3N NaDH time is 15 minutes with 18 0.4N " a ratio of 2 II N 7 H N H 1. These experiments seem.to show that the gram load at 29.80 C. H H H I! gram load at 39° C. II II I! ll swelling of wool fibers is not connected with such an irreversible chemical change as the rup- ture of cystine linkages. This is shown by the fact that no contrac- tion was observed when wool yarn was immersed in thioglycollic acid, which is known to reduce the cystine linkages. The Stretch Behavior of W001 Yarn The stretching of wool fibers is a physical change which may be completely physical, or it may be the result of chemical changes, some of which are partially reversible and others are completely irrevers- ible. It was shown in the Introduction that the wool molecule has two physical forms, the normal relaxes structure, and the extended or un- folced structure. When a stretching load is applied to a wool fiber the first thing that happens is the conversion to the extended structure. This is purely a physical change, and it has its limit. That is, there is a limit to the amount of elongation that can be given to wool fibers. They may be stretched to the extended form, but no farther, because the distance between atoms in a molecule cannot be increased by physical stretching. Some physical stretching can be attributed to the sliding past each other of some un-cross-linked molecules or chains, but it is not known to what extent this may play a part in the elongation of wool fibers. The only way to get more stretching is to rupture cross-link- ages which bind parallel polypeptide chains together in the molecule. The stretching of wool fibers over and beyond the physical maximum requires chemical reaction, and in the present experiments this is brought about by the action of alkali. Sodium hydroxide can act upon wool in two ways: A. The splitting of cross-linkages. The salt linkages in wool are salts of weak acids and weak bases, which are hydrolyzed in alkaline solutions. If the concentration of OH ions is great enough the salt 74 will be hydrolyzed and the weak base liberated. After such chemical reaction the un-linked parallel chains may slide past each other, per- mitting some elongation of the fiber. Many of these ruptured salt linkages may be rebuilt later, that is, after a reasonable amount of distortion has taken place and alkali has been removed, new salt link- ages may be formed. This kind of stretching is therefore brought about by'a more or less reversible chemical change. The most important cross-linkage in wool is the cystine or disul- fide linkage. This is also broken by the action of sodium.hydroxide, forming sulfhydryls and unstable sulfenic acids. If this happens it is obvious that parallel polypeptide chains are permitted to slide past each other with the resulting stretching of the wool fiber. When this reaction takes place, the cross-linkage cannot be rebuilt after the alkali has been removed. Therefore stretching due to such a re- action is permanent, and the wool has been permanently damaged. Both of these cross—linkage-splitting reactions take place first and most easily in the amorphous regions of the wool fiber, after which similar reactions will occur in the crystalline portions of the fiber. Since these are chemical reactions, their rate and extent will be dependent on the concentration of reactants and the temperature. The concentration of wool (one reactant) may be considered as a constant, and therefore the observed stretching behavior of wool fibers should depend on the concentration of alkali. That is, more stretch, and in a shorter time, should result from higher concentrations of a NaOH solutions. 75 B. The rupture of polypeptide chains. It is well known that wool can be completely degraded by the action of alkalies into a mixture of amino acids. This is brought about by alkaline hydrolysis, but it re- quires considerable time, or high temperatures. When sodium.hydroxide acts on wool in this manner it is no longer a matter of elongation or stretching, but is one of actual breaking. If the main strength-giving chains of wool are torn apart, there is no strength left in the fiber. This is a slow reaction and considerable time is required before its effect becomes notices, but after such a time is reached, there is a very great increase in stretch, followed by the breaking‘of the yarn. For example, in 0.4N NaOH at 39° C. with a load of 42 grams wool yarn was found to stretch in a fairly regular and slow manner for about 40 minutes, at which time it had stretched 25,9. Then all of a sudden it began to stretch much more rapidly and within a few seconds had stretch- ed to over 40% and broke. These experiments give quantitative evidence of what would be ex- pected of the stretch behavior of wool yarn in alkaline solutions at different temperatures. They show that wool stretches more easily and rapidly in solutions of higher concentrations, and at higher tempera- tures. Effect of Load on Stretch and Time Some interesting conclusions can be drawn if we study the effect of changes in stretching load on the percent stretch at the breaking point and the time required to reach the breaking point. These relation- ships are shown by the curves on Graphs 15 and 16 for 29.80 C. 76 On Graph 16 stretching load is plotted against the percentage the yarn has stretched at the time it broke. Curves are plotted for three different concentrations of NaOH, 0.4N, 0.5N and 0.75N. The three curves are practically straight lines, which shows that the percentage of stretch at the breaking point varies almost directly with the load applied. The three curves are also pretty much parallel, which shows that this relationship holds good regardless of the concentration of alkali. It is seen that, with greater loads, the curves are closer together, which means that the change in concentration is of less imv portance than the change in load. On Graph 18 similar curves are plotted for the higher temperature. There appears to be less of the straight-line relation between load and percentage of stretch at this higher temperature, since the curves are not as nearly straight lines as they are at the lower temperature. However, they are still fairly parallel. The greatest difference be- tween the curves for the two temperatures is the distance between them. There is no doubt that, with the same loads, the effect of changes in concentration of alkali, is more noticeable at the higher temperature. 0n Graph 15 stretching load is plotted against the time required for the yarn to break. It is apparent that the time required for the yarn to break is not directly proportional to the load applied. This is specially true with the lower loads, but when the loads are greater than about 120 grams, the relationship is about straight-line. If we change the load on a yarn we can predict fairly well how much it will stretch before it breaks, but the time required is not the expected length of time with lower higher temperature. In order to Show the temperature the following for a 42 gram load in all centrations and temperatures. loads. camav‘wam: q 37." C31 3.; :". : figures are given. L I ‘\ I ‘l The percentage and time been converted into simple ratios in each case. 42 gram load 0.75N Percent stretch 34 at the break Time required 12 to break 29.80 c. 0.5N 0.4N 25 17 4 42 85 2 42 gram load 59° c. 0.51% Percent stretch 46 at the break Time required 15 to break 0.4N 0.5N 29 10 9 58 115 l conclusions This is still more apparent at the and These figures are those cases, and they refer to the indicated con- figures have ratio .0 fl 0. 14 ratio u O) .0 N u (N n (O The spread of the ratios clearly illustrate the foregoing conclu- sions. final Condensed Results Wool yarn, under various stretching loads, has been subjected to the action of solutions of some alkaline and reducing compounds at 29.80 C. and 39° C., and its contractile and stretch behavior observed. in sodium hydroxide solutions of 0.2M to 0.75N there is an initial, fairly rapid and s'gnificant contraction of the yarn, which is followed by stretching, and the yarn may or may not break. The extent of this contraction increases with an increase in concentration of NaCH up to a maximum with about 0.3N to 0.4N and then starts to decrease. The maximum contraction was 3.25% in 0.5N NaOH at 29.80 C. with a load of 18 grams. This contraction was not observed in solutions of Ea2005, nor with reducing agents such as sodium.hydrosulfite or thioglycollic acid. The rate and extent of stretch in NaOH solutions increased with the concentration of NmOH, and with the temperatures. Two extremes are: 18 gram load at 29.80 C. in 0.2N NaGH gave no stretch up to three hours. 0 0 r’1 ' .77 ‘r 1' 72 gram load at 39 C. in 0.7ofi haOn gave 5b” stretch and broke in seven minutes. In solutions of Nagcos up to 1.0N there is no contraction with an 18 gram weight, and no stretch up to three hours even with 190 gram weight. In thioglycollic acid at 29.80 C. a weight of 190 grams was required to obtain a stretch of 4.5% in three hours. However, at 39° C. in 0.5N solution a weight of 150 grams gave a stretch of 31% in three hours, 79 and in 0.753 solution a stretch of dlfiwas obtained with a load of 190 grams in three hours. In no case with thioglycollic acid did the yarn break. l. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 80 BIBLIOGRAPHY Alexander, J., Ind. an. Chenn, 31, 630 (1939). Astbury and Bell, Nature, 14], 696 (1941). Astbury and Woods, Nature, 131, 665-5 (1951). Astbury and Woods, Trans. Roy. Soc. (London), A232, 333 (1933). Barritt, J. Soc. Chem. Ind., 31, T69 (1928). Barritt and King, J. Text. Inst., 1], T366 (1926). Consden, R., J. Text. Inst., 49, P814-P830 (1949). Harris, nilton, Ind. Eng. Chem., 33, 833 (1942). Harris, Milton, Ind. Eng. Chem. 34, 1398 (1942). harris, Hilton, J. National Bur. tandards, 1g, 63 (1936). Harris, hilton, J. National Bur. Standards, 1gp 301-9 (1936). harris and Brown, Ind. Eng. Chem. 49, 316-322 (1949). Harris and Mizell, Ind. Eng. Chem. 34, 434 (1942); §§, 836 (1942). 0 Hartsuch, Bruce 3., Textile Chemistry, John Wiley a Sons, New York, 1950. Lindley and Phillips, J. Biochem., £2, 17—25 (1945). Mizell and Harris, J. Research National Bur. Standards, 30, 47-53 (1943). '_‘ Patterson, Geiger, Mizell, Harris, J. Research National Bur. Standards, 27, 89 (1941). Speaksman, J. 3., J. Text. Inst., 32, T83-108 (1941). Speaksman, J. 3., J. Text. Inst., 34, T70 (1943). Speaksman, J. 6., Nature, 124, 948 (1929). 1 a K .- 0 f o o O . D ' r, O Q I a Q Q 0 O t V o 1 ‘ '1 O O , ° t ('1 ‘ t 0 c I Y a r. I O o " O I 9 O 21. 22. Sneaksman, J. 5., J. Text. Inst., 21, A170 (1930). Sponsler and Dore, X-ray. r.- _: n. r) h1n Von womnrn, K011. salt, 40, 120 (194.). 81 e; NOV 8 M 01 0321113191 mom! q? . .‘J'y EVE: ,AC‘ . 1,: 3' Of; ‘1 Ou’lJa. 0 299041 31293 02446