sppt. 1949 FARNWORTH, NEISH & SPEAKMAN-"SULPHUR LINKAQE IN ANIMAL FIBRES-VI" 447

The experiments described and discuseed in this paper are put forward as a preliminary survey of the subject. They serve to confirm the value of a new experimental method for investigating dye transfer processes, specifically in printing opera- tions, but more generally over ranges of dye and salt concentration not normally encountered in dyeing, and with very small volumes in the p h w external to the fibre substance. Work has already been extended to other thickeners and to other classes of dyes, and it is possible that useful information will also be obtained in studies of the transfer between thickener and cellulose of sub- stances, other than dyes, which are present in printing pastes. Two subjects dealt with briefly in the present paper, viz. desorption processes and the electrical conditions at the interphase boundary, are regarded as important and are held to be worthy of much more detailed examination.

We wish to express our thanks to the Corpora- tion of Manchester for the award of a Research Scholarship in Technology, which has assisted one of us (R. H. M.) to participate in this work. DEPARTMENT OF TEXTILE CHEMISTRY

COLLEGE OF TECHNOLOGY MANCHESTER

(Received on 8th February 1949)

References GImum, AWT. Dyflstuff Rep., 1934. 23, 176. Idem, &id.. 1936,25, P 160.

Idem, ibid., 1937, 26, 124. Idem, &id., 1937, 26,437. Idem. &id.. 1938. 27. 303.

* Idem, ibitl., 1937, 26, 33.

MacNeider, Ind. Eng. Chem., 1912, 4, 417. lo Kerr, The Chemistry a d Induetry of Starch (New York:

Academic p1.ess Inc., 1944). l1 Radley, Starch and it-9 Derivatives (London: Chapman

& Hall Ltd., 1940). la Willismson, I d . Eng. Chem., 1929, 21, 1108; 1931, 23,

667. la Bingham, J. Phye. Chem., 1926, 29, 1201;

Bin hem and Green, Proc. Amer. Soc. Testing Materiale, If 1931, 19, 640

14Shioher, J. Appl. Chem. (U.S.S.R.), 1946, 19, 242: this Journal, 1947, 63, 247.

Is urquhsrt, J . Text& Inel., 1943, 34, T 103. 10 Meggy, thh Journal, 1943, 59, 192. 1? Rupp, Anwr. meutuff Rep., 1932, 21, 343.

lo Garber and Qriin, MeUiOnd Tertilber., 1939, 20, 434. * O Qlemtaen. AWT. Dueutuff Rev.. 1939. 28. 280.

Strachan, aid.. 1938, 27, 240.

'I Shirev, Tebat8til. P&.,""l947', $, (2); 27; this J o u m l ,

IP Rogers, M. Sc. Teoh. T h i s , Manchester University, 1947, 63, 334.

1947. 1942. *a Meggy.and Rogem, this J o u d , 1943,59, 216. I4 Jacoby, Amer. Dpatuff Rep., 1944.33, P 602. '6 Qardner, Bbchmg, OJeing, and Calico Printing

(London: cherlee Ur& & Co. Ltd., 1884), pp. 83,135. Gleysfeen, Amer. Qwtuf Rep., 1938.27, 14. hrber, MeUiond Textilber.. 1940, 21, 76.

*a Cibo Review, 1941, (41), 1606. *@ Schomeyer, Felton, and Cord, Ind. Eng. Chem., 1943,

35. 1168. I0 Ta&mni, this Jw~noZ. 1929, 45, 347. a1 Hoyle, ibid., 1941, 57. 43. I* Doyle, M . Sc. Tech. Theeie, Univemity of Manchester,

Neale e6 d., T m . Famday Soc., 1933, 29, 1167; 1936,

a4 Mills and Robinson, Proc. Roy. Soc.. 1931, A 131, 676. asBodton and Reedinn. this Journd. 1934. 50. 381;

1942.

31, 1718; 1947, 43, 332.

%,. . . 1838. 54. 268.

BoGbon.-&lph. Fothergill. and Morton, J. Textile Inat.,

Neale. Tram. Famdau Soc.. 1946. 42. 473: 1933.24. P 113.

Oady; ibid.; 193Ri 27, P 669. . Neal0 and Peters, ibi;2., l946,42, 478; Neale, aid., 1947.43, 326. Neale, thia Journd, 1947.63, 368.

I0 C C ~ C . W., 1947, 63, 412; 1948, 64, 386.

8 Knecht and Fothergill, The. P~ in~ip lee and Praclice of Textile Printing (London: Charles Griffin & Co. Ltd., 1936), p. 160.

The Reactivity of the Sulphur Linkage in Animal Fibre8 VI-The Cause of Unshrinkability

A. J. FARNWORTH, W. J. P. NEISH, and J. B. BPEAKBUN . . In order to teat the view that reagents such aa chlorine, sulphuryl chloride, and sodium hydroxide

make wool unahrinkable by promoting disulphide bond breakdown in the surface of.the fibres, the action of these reagents on wools containing other types of cross-linkage in place of cystine haa been examined. Four kinds of wool have been used, viz. (1) wool reduced with thioglycollic acid and treated with mercuric cyanide to form -S*Hg.S- crow-linkeges, (2) wool reduced with thioglycollic acid and treatad with trimethylene dibromide to form biethicether croee-linkages, (3) alknli-treated wool containing lanthionine and, presumably, -CH:N- crow-linkages, and (4) wool treated with poteesium cyanide to convert most or all of the cystine into lanthionine. In all cases, the m o d 8 4 wool was more difflcult to make unshrink- able than untreated wool, though the difference waa small with types (1) and (2). Very sucoeesful results were obtained with the alkali-treated wool (3). and complete immunity to the action of chlorine, sulphuryl chloride, and potassium hydroxide, aa regards the development of mistance to shrinkage, was obtained with wool treated with potassium cyanide (4). teeeium cyanide is to convert disulphide bonds into lanthionine cross-linkages, there can be little g u b t , therefore. that the above reagents make normal wool unehrinkable by causing disulphide bond breakdown.

Since the action of

One of several general methods of making wool unshrinkable depends for its success on the forma- tion of a gelatinous degradation product of keratin on or under the surface scale structure of the fibres. As a rule, the necessary degradation is brought about by chlorine, the layer of cortex immediately underlying the scales being attacked preferentially when an aqueous solution of chlorine is usedl. The attack may, however, be restricted to the surface

of the fibres by taking advantage of the inaccesei- bility of dry fibres to reagents of comparatively low molecular weight*, as, for example, in the pro- cesses where gaseaus chlorine3, or solutions of chlorine in inert organic solvents, are applied to wool of low water content.

From first principles it is evident that the degradation essential for unshrinkability must be realised by fiesion of disulphide bonds or peptide

448 FARNWORTH, NEISH C SPEAKMAN-"SULPHUR LINKAGE IN ANIMAL FIBREB-VI" a p t . 1049

linkages, and since chlorine is capable of attacking both, it was at first uncertain which reaction is the more important. Chlorine dioxide, which converts cystine into cysteio acid, is, however, believed to be incapable of attacking peptide bonds, and a solution of chlorine dioxide in carbon tetrachloride was found to make wool unshrinkable4. When, in addition, it was shown that potassium permsn- ganite, manganese heptoxide, and Caro's acid can be used to make wool unshrinkable, it became clear that any oxidising agent which is capable of causing disulphide bond breakdown is a potential agent for producing unahrinkability5.

The fundamental importance of disulphide bond breakdown as a cam of unahrinkability was still further emphasised by the investigation which waa undertaken as soon as Hall showed that wool can be made unshrinkable with a solution of sulphuryl chloride in white spirits. When the action of sulphuryl chloride on a simple disulphide was investigated, disulphide bond fission was found to occur in presence and absence of water'. At this stage, therefore, it was possible to conclude that "any reagent capable of causing disulphide bolid breakdown, preferably without re-forming linkages . between the peptide chains, may be utiIised to impart an unshnka ' ble fmbh to ~ 0 0 1 " ~ . More recent work, especially Hudson and Alexander's examination of the action of fluorine on woole, cmphasises the validity of this conclusion.

In order to obtain conclusive proof of disulphide bond breakdown as the fundamental cawe of unshrinkability in processes of the type now under consideration, the converse problem of preventing the development of unshrinkability has been- studied at intervals during the past six years. The general principle underlying the work was as follows- if djsulphide bond fission is the cause of unshrinkability , the conversion of disulphide bonds into less reactive cross-linkagea should make it impossible to obtain an unshrinkable finish when the modified wool is treated with reagents such as chlorine, sulphuryl chloride, and sodium hydroxide. Four types of modified wool have been examined, viz. wools in which the disulphide bonds were replaced by the following cross-links-

(3) -CH,.S.CH, (using alkali), and (4) -CH2.S*CHs- (using potassium cyanide). A preliminary note on the results obtained with the type (3) wool has been published elmwhere*, and the following more detailed account is included for the y k e of com- pleteness.

(1) Mercaptide Cross-linkages

(1) -CH2.S.Hg*S.CH*-, (2) -C&*S* [CH, L*S*CH2-,

(a) FORMATION OF YERCAPTIDE CROSS- LINEAGES

Some years ago it was shownl0 that stretched animal fibres can be given a permanent set at low temperatures by treatment first with a reducing agent to cauae disulphide bond breakdown-

R-CH,&S.C%-R + 2 NaSH + 2 R.C%.SH + N~pf3, and then with a metal salt to form metal-oon- taining cross-linkages between the peptide chains of the relaxed fibres-

R.C€&6H + MX, + HS-CWR-t R . C q M * C W R + 2 HX Similar r&wtions take place in unstretched fibree, and mercuric acetate is singularly eflectivc for linkage rebuilding. It is, however, capable of strengthening intact fibresll, presumably by cross- linking basic, acidic, and amide side-chains, and it seemed desirable for present purposes to use a metal salt capable of selective reaction with thiol side-chains. After much preliminary work, which need not be described, mercuric cyanide waa finally found to be capable of cross-linking reduced fibres, though it differs from mercuric acetate in being incapable of cross-linking intact fibres. The behaviour of mercuric cyanide in reaction with both types of fibre is illustrated by the following experiments.

Human hair fibres, which had been calibrated by determining their load+xtension curves up to 30% extension in distilled water at 22.2"0., were treated for 6 hr. a t 2 2 ~ 2 ~ 0 . with either (i) a 0.1 M. solution of mercuric acetate in 0.1 N. acetic acid, or (ii) a 0.1 Y. solution of mercuric cyanide in water, before being washed in running water and then restretched in distilled water a t 22.2%. The observed changes in resistance to extension due to the treatments are given in Table I.

TABLE I Change in ResiHtance

(%) Yercnrlc ncetate ... ... 6.1 Mercuric cyrnlde ... ... - 4.0

Reagent to Extension

After treatment with the solution of mercuric cyanide for 5 hr. at 60"a., the change in resistance to extension (c .R.E.~ waa - 7.6%, the increased damage being due, no doubt, t o dilisulphidc bond attack at the higher temperature; but even when the treatment was carried out for 24 hr. a t 22*2"c., no strengthening was obtained, the C.R.E. being

Reduced fibres, on the other hand, are readily cross-linked by mercuric cyanide. After calibration, human hair fibres were reduced for 2 hr. a t 50"c. with a solution (pH 4 6 ) made up by mixing equal volumes of potassium hydroxide (2 M.) and thio- glycollic acid (2 M.). The fibres were then washed in running water for 3 hr. At this stage, two of the fibres were treated for 5 hr. at 22-2"o. with a 0.1 M. solution of mercuric cyanide (pH 5-9) and then washed in running water overnight. For reference purposes, a second pair of reduced fibres was also given an overnight wash in running water, and the four fibres were finally restretched in distilled water a t 22.2'0. Values for the C.R.E. are given in Table 11.

- 2.4%.

TABLE II Change In ~ l s t a n c e

(%) Treatment to Extension

Reduced and washed ,,. ... - 48.0 Reduced treated with mercuric

cysiide, and washed ... - 16.8

After it had thus been shown that mercuric cyanide is capable of cross-linking reduced fibres, presumably with formation of S*Hg-S- cross- linkages, attention was turned to the action of

chlorine, sulphuryl chloride, and sodium hydroxide on treated fabric.

(a) SHRINKAGE TESTS

The flannel used in this section of the investiga- tion had the following construction-

Warp ... 28.6s Yorknhlre akelns; 36 ends per In. Weft ... 26.66 Yorknhlre ekelna; 33 ends per In. Weave ... Plaln Weight ... 6 4 0 oe. per sq. yd.

After reduction in 200 C.C. of a 1.0 M. Solution of potassium thioglycollate a t pH 4.6 for 2 hr. a t 60"c., two 2.6-g. samples of flannel were washed in running water for 15 min., in phosphate buffer a t pH 8 for 15 min., and finally in running water for 160 min. The samples were then centrifuged, and immersed in 200 C.C. of 0.1 M. mercuric cyanide solution for 24 hr. a t 22.2"~. At the end of this time the solution smelt strongly of hydrocyanic acid, and the samples were washed in running water overnight. One pattern was.then chlorinated under the following conditions-

CHLORINE- After immersing the wetted-out pattern in 100 C.C. of a phthalate buffer solution at pH 4, 50 C.C. of a solution of sodium hypo- chlorite, containing 4% of available chlorine on the weight of the wool, was added from a burette over a period of 10 min. In order to promote uniform chlorination of the wool, the mixture was shaken during the addition of hypochlorite and for 10 min. afterwards. The pattern was then transferred to a 1% solution of sodium bisulphite for 6 min. to remove excess chlorine, neutralised by immersion in 0.6y0 sodium bicarbonate solution for 6 min., .and finally washed in running water overnight. An untreated pattern was chlorinated under the same conditions, and the three patterns, with an untreated control, were hand-milled for 16 min. in 6% soap solution. The resulting shrinkages are given in Table 111. Included in the table are data from corresponding experiments which were carried out to compare the actions of (a) sulphuryl chloride and (a) sodium hydroxide on treated and untreated patterns. Details of the treatments am given below.

SULPHURYL CHLORIDE- Each 2.6-g. sample of untreated or modified wool was conditioned a t 6Syo R.H. and 22.2'0. before treatment fo? 1 hr. at 22.2%. in 100 C.C. of a 2.5% (v/v) solution of sulphuryl chloride in carbon tetrachloride. The pattern was then washed in three 100-c.c. lots of carbon tetra- chloride for 5 min. each time, neutralised in two 100-c.c. lots of 0.5 yo sodium bicarbonate solution for 6 min. each time, and finally wmhed in running water overnight. SODIUM HYDROXIDE- Each 2.6-g. sample of

untreated or modified wool was conditioned before treatment for 3 hr. a t 22.2'0. with 10 C.C. of a 7% solution of sodium hydroxide in butyl alcohol diluted to 100 C.C. with white spirit1*. After treat- ment, each pattern was washed in three 100-0.c. lots of carbon tetrachloride for 6 min. each time, centrifuged, and then acidified by immersion in 0.2 N. eulphuric acid for 6 min. Before being miUed, the patterns were washed in running water overnight.

"he shrinkages given in Table I11 are expressed in two ways, viz. (i) as percentages of the original are- of the patterns* and (ii) as percentages of the areas of the patterns immediately before milling.

TABLE I11 Percentage Shrinkage

In Area Reatanent (1) (U)

None . . . . . . . . . . . . . . . . . . 3 3 4 33.4 Chlorlne . , . . . . . . . . . . 4 4 3.8 Reduced aud eydr&&atad . . . . . . 21.1 18.0 Reduced, eysnfde-.treated, and chlorinated ... 12 1 7 4 None . . . . . . . . . . . . . . . . . . 36.1 30.1 Sulphuryl cN0ride . . . . . . . . . . . . - 4.5 - 2.7 BadUmd and cyanlde-tmtad . . . . . . 22.0 18.4 & d u d Cydde-tWted, and sulphml

ehlohde . . . . . . . . . . . . . . . 6.8 1.7 . None . . . . . . . . . . . . . . . . . . . 36.2 36.2

Reduced and eyanlde-treated . . . . . . 21.1 17.4 BRdnmd, cyanfde-treat%d snd W u m

. . . . . . Wlum hydroTIde dhperslon 7.3 5.8

hydrollde dlspeauiod . . . . . . . . . 18.6 6.6

After treatment with chlorine, sulphuryl chloride, or the sodium hydroxide dispersion, the shrinkage of the redud and cyanide-treated patterns is always greater than @at of the corresponding normal patterns. The differences are, however, disappointingly small. This is due, in part, to the diminished shrinkage of the fabric after reduction and treatment with mercuric cyanide, which must be referred to incomplete linkage-rebuilding, as shown above. In addition, the mercaptide link. ages may be ruptured by the reagents used to make the wool unshrinkable. This is certainly true of the sodium hydro4ide dispersion, because the cyanide- treated pattern developed black streaks during treatment and were stained yellow-brown after acidification with 0.2 N. sulphuric add.

In an attempt to obtain more conclusive results, attentiorrwas next turned to the behaviour of wool containing biathioether cross-linkages.

(2) Biethioether Cross-linkages I n previous work on the setting of strained

animal fibm at low temperatures, it has been shown that reduced fibres may be cross-linked by means of ''an organic compound containing two or more reactive halogen atoms'llO. Pattemon, Geiger, Mizell, and Harris afterwards applied this method of modifjing the properties of wool to wtretched fibres, using thioglycollic acid as the reducing agent and compounds such as tri- methylene &bromide for linkage rebuildinglS. In later experiments, calcium thioglycollate was used &B the reducing agentla, and this method of pre- paring wool containing bisthioether cross-linkages was adopted in the following experiments.

(a) FORMATION OF BISTHIOETHER CROSS- LINKAGES

Each pair of calibrated human hair fibres was treated for 2 hr. at 60'c. in 10 C.C. of 0.3 N. calcium thioglycollate. The fibres were then washed in running water for 6 min., in phosphate buffer (pH 8) for 6 min., and in running water for 20 min. Alkylation waa oarrid out by transferring the fibres to a vaouum flmk containing 300c.c. of

A f h relaxation In water, IM wlU be clear from the reaulta.

450 FARNWORTH, NEISH & SPEAKMAN-"BULPIIUR LINKAGE IN ANIMAL FIBRES--VI" scpt. 1949

phosphate buffer (pH 8) and 2 C.C. of trimethylene dibromide. During the 2-hr. treatment, the flask was ehaken in a revolving shaker and the tempera- ture fell from 50%. to 44%. The fibres were then removed, washed in running water for 30 min., dried, and again reduced in 10 C.C. of 0.3 N. calcium thioglycollate. After a second alkylation under the same conditions as before, the fibres were washed in running water overnight. Two more treatments with thioglycollate and trimethylene dibromide were carried out on the following day, followed by an overnight wash in running water. The proper- ties of the fibres, and pairs which were removed at each stage of the complete sequence, were then 'examined. For reference purposes, reduced fibres were treated with the buffer solution alone in a parallel experiment.

(i) RESISTANCE TO EXTENSION- The load- extension curves of the treated fibres were redeter- mined in water a t 22-2"0., and values for the O.R.E. are given in Table IV.

TABL4 I V (nisnue In ReRiHtaiice to Extension

Buffer Reductions Rehiiildlngs Series Serlerm

Treatment (%) No. of No. of Dlhnllde

1 1 1 2 1 2 2 3 2 3 3 4 3 4 4 '

- - 2 7 4 - 23.8 - 15.3 - 18.1 - 35.0 - 43.3 - 26.8 - 30.8 - 20.0 - 4 1 4 - 26.1 - 34.2 - 26.0 - 43.1 - 22.2 - 32.0

Even after four treatments with the reducing agent and trimethylene dibromide, the fibres are considerably weaker than untreated hairs, and on comparing these results with those of Table 11, it is obvious that mercuric cyanide is very much more effective than trimethylene dibromide as a linkage-rebuilding agent. Similar results to the preceding were obtained when the fibres were reduced with M. thioglycollic acid at pH 4-5 for 24 hr. a t 25%. or for 2 hr. at 6O"c., the C.R.E. after three 24-hr. treatments with trimethylene dibroniide and buffer at room temperature being - 22.0 and - 27.1% respectively.

(ii) SUPERCONTRACTION - Supercontraction meiisurements were carried out: in the usual way and the results are given in Table V.

T A B L ~ V

Treatiiirnt (%) No. of No. of Dlhaltde Liuffer

Reduction8 Itebulldlngs Serlea Series

20.0 2 0 0 1 1 0.5 . 24.7

0.2 22.8 2 2 0.2 24.0

0.2 24.4 3 3 0.0 20.8

0.0 16.7 0.4 224 - 22.0

4 4

Supercontractlon

1 - 20.9 i20.9

The cross-linkages formed by the buffer are clearly unstable in a boiling solution of sodium bisulphite, and the difference in behaviour of the two series of fibres confirms the presence of bisthioether cross- linkages in dihalide-treated fibres.

( b ) SHRINKAGE TESTS

In the light of the preceding experiments, each 2.5-g. sample of flannel, with calibrated human hair fibres attached, was reduced in 1OOc.c. of 0.3 N. calcium thioglycollate a t pH 4.3 for 2 hr. a t 6 0 " ~ . The sample was then washed in running water for 10 min., in phosphate buffer (pH 8) for 5 min., and in running water for 16 min. After the pattern had been centrifuged, i t waa alkylated for 2 hr. a t 60% in a suspension of 2.6 C.C. of tri- methylene dibromide in 1 litre of phosphate buffer solution (pH 8). The flannel was then washed in running water for 30 min. before repeating the above procedure. Four successive reductions and alkylations were carried out, fibres being removed at each stage to follow the course of diaulphide bond breakdown and linkage rebuilding. The results are given in Table VI.

TABLl VI Treatment Change In Reslnhnce

to Extenalon No. of No.,of Reductions Rebulldlnp (%)

- 1 - 17.8 1 1 . - 10.6 2 1 - 25.0 2 2 - 1 7 3 3 2 - 30.8 3 3 - 23.9 4 3 - 35.5 4 4 - 23.2

It is satisfactory that fibrm treated at the same time as the flannel give the same final C.R.E. as those treated alone, and it seeme probable, there- fore, that the fibres of the flannel contained thc maximum number of bisthioether crowlinkages it is possible t o form under the above conditions.

Accordingly, samples of flannel which had been given four successive treatments with calcium thioglycollate and trimethylene dibromide were treated with chlorine, sulphuryl chloride, or the sodium hydroxide dispersion under the conditions already described, except that in the last, caso the liquor ratio was 20 : 1. Similar experiments were also carried out with samples which had been treated with buffer alone after each reduction, and the results of milling tests are given in Table VII. The treatments with sulphuryl chloride and sodium hydroxide dis rsion were, of course, carried out on patterns w lr 'ch had been conditioned for a t least 48 hr.

The results of the dihalide series are satisfactory in showing that wool containing bisthioether cross- linkages is more dil€icult to make unshrinkable with chlorine and sodium hydroxide than untreated wool. Positive results are also obtained with sulphuryl chloride, but the differences between untreated flannel and flannel containing bisthio- ether cross-linkages are disappointingly small. The reduced and buffer-treated samples seem also to be a little more resistant to chlorine and sulphuryl ohloride than untreated wool, but there is a dramatic difference in behaviour of dihalide- and buffer-treated samples with the sodium hydroxide dispersion. The difficulty of making woo1 unshrinkable with sodium hydroxide after some, at least, of the cpt ine linkages have been converted into bisthioether cross-linkages is,

~cpt. 1949 FARNWORTH, NEISH & SPEAKMAN-"SULPfIUR LINKAGE IN ANIMAL FIBRES-VI" 461

TABLE V I I Shrinkage in Area

(i) (11) DIHALIDE RERIES

None . . . . . . . . . 27.5 27.6 Chlorine . . . . . . . . . 3.5 1.7 Reduced and alkylated ... 274 20.0 Reduced alkylated, and

Treatnirnt (%)

chlohn8ted . . . . . . 18.5 B.2 (1) (11)

None . . . . . . . . . 33.5 33.5 34.8 34.8 Sulphuryl chloride ...- 1.0 - 2.0 - 6.4 - 5.4 Reduced and dkyl8t8d .:. 28.1 27.0 26.8 21.7 Reduced alk lated and

sulphuryr ch1o;ide ... 10.0 1.7 7.8 0.9

None . . . . . . . . . 31.8 31.8 . Reduced and alkylated ... 36.1 263 Reduced alkylated and

Elodlum hydroxide ... 15.7' 1.0

sodlim hyddlde ... 28.4 174 .

BUFFER SERIES

Noiie . . . . . . . . . 31.0 31.0

(3) Lanthiohe and -CH:N- Cross-linkages (a) FORMATION OF CROSS-LINEAGES

It has already been shown that, when human hair fibres are treated with 0.1 N. sodium hydroxide solution at 22*2"c.,. the extent t o which the fibres supercontract in a boiling 6% solution of sodium bisulphite decreases with increasing time of treat- ment until, after 10 hr., supercontraction & pre-

(1) (11) 9,8 37.0 ventedlb. The absence of supercontraction was 3.6 1.0 referred to the formation. of ->C*S.C<- cross-

32.6 27.5 linkages, whose egistence has since been confrmed by Horn, Jones, and Ringel's isolation of hnthionine from alkdi- tmted fibres's. Phillips afterwards suggustkd that -CH:N- cross-linkages might also be formed according to the following scheme''-

6.3

>CH-C&*S*S*CQ.CH< + -0 --+ >CH*CH,*S*OH + HS*CZ&*CH< >CH*CI&-S*OH -+ >CH.CHO+H@

>CH.CHO + KN*[CH,L*CH< -+ >CH-CH:N.[CH,],CH< + H,O Chlorlno . . . . . . . . . 6.1 2.7 Reduced and buffer ... 33.5 26.4 Reduced, buffer, and

chlorinatod . . . . . . 16.0 8.0

None . . . . . . . . . . 40.3 40.9 Sulphuryl chloride ... 2 5 - 1.9 Reduced and buffer ... 3&1 32.1 Reduccd buffer and

None . . . . . . . . . 27.5 276 Sodlum hydroxlde ... 19.0. - 1.0 Reduced and buffer ... 28.8 22.3 Reduced, buffer and

sodium hydroxide ... 2 5 4 - 15.8

Thwe high values are due to ahrinkage during treatment with the sodium hydroxide dispersion the sMnkaue belng abnormally Ngh owlnu to the prcsence of w&r in the solvents.

%ulphuryl ehloride ... 11.1 3.8 .

in fact, so great as to leave no doubt that the unshrinkability conferred on untreated flannel is due to disulphide bond breakdown.

It seemed probable that the inconclusive results obtained in the preceding experiments with sulphuryl chloride and, to a lesser extent, chlorine, were due to two causes- (a) incomplete reduction of cystine and, more important, (b) incomplete formation of bisthioether cross-linkages from such cystine as wm reduced. Besides promoting shrink- age during the reduction-alkylation processes, as may be seen by comparing the data in columns (i) and (ii) of Table VII, incomplete linkage-rebuilding leaves intact disulphide bonds more open to attack by the reagents afterwards used to make the wool unshrinkable. Damage is always to be expected when disulphide bond breakdown is separated from linkage-rebuilding, because the structure is so easily disorganised, especially a t high temperatures, while the cross-linkages are broken. Even if the disorganised structure could be cross-linked to just the same extent 88 on0 in which molecular rearrangement is prevented, weakening would still be the result. Damage is therefore less likely when disulphide bond breakdown and linkage-rebuilding proceed simultaneously, for then the degree of breakdown at any instant is never such as to permit gross molecular rearrangement. For these reasons, the behaviour of alkali-treated wools in reaction with chlorine, sulphuryl chloride, and the dispersion of sodium hydroxide was noxt examined.

Evidence for the presence of some -CH:N- linkages, in addition to the lanthionine croes-linkages, was provided by the fact that fibres treated with caustic soda, which fail to contract in a boiling solution of sodium bisulphite, contract after being subjected to treatments calculated to break the -CH:N- cross-linkageds. For example, =ustic-soda-treated fibres', after being boiled in 0.2 N. hydrochloric aoid for 30 min., contraoted 16%, and treated fibres boiled in 0.1 N. pyruvic acid for 1 hr. contracted la%, in a boiling 6% solution of sodium bisulphite. The incompleteness of the supercontraction did, however, indicate the presence of other, more stable cro'oBB.lhkagea, viz. lanthionine. More recently, P W ~ B has been led to conclude that -CH:N- crose-hhges are not 'present in alkali- treated fibreslo, but even if his conclusion were accepted in face of the preceding evidence, there can be no doubt that the cystine linkages of intact fibres are repltcced by lanthionine and other cross- linkagw when the fibres are treated with 0.1 N. sodium hydroxide In the cold. During such treat- ment, disulphide bond breakdown end linkage rebuilding proceed side by side, and it seemed probable, therefore, that alkali-treated flmnel would be more suitable than the treated flannels already examined for the purpose of deciding the part played by dieulphide bond breakdown in making wool unehrinkable.

(b) EHRRYKAOE TESTS

Pairs of 2.5-g. patterns of flannel were treated with 2 lit- of 0.1 N. sodium hydroxide solution for 1, 3, 10, or 24 hr. at 22*2"0., the solution being renewed after 6 hr. in the 10-hr. treatment -and after 10 hr. in the 24-hr. treatment. After the treated patterns had been washed in running water overnight, centrifuged, and conditioned, one pattern from each pair was treated with chlorine, sulphuryl chloride, or the sodium hydroxide dis- persion in the usual way. Untreated patterns were also treated with the same reagents for inclusion in the milling tests, which gave the results shown in Table VIII.

In all (18888, the ability of the flannel t o acquire an unshmh ' ble finish is reduced very considerably by previous treatment with 0.1 N. sodium hydroxide

452 FARNWORTR, NEISH & SPEAKMAN-"SULPHUR LINKAGE IN ANIMAL FIBRE&-VI" b p t . 1040

TABLE MI1

hhne . . . . . . . . . 36.4 '36.4 30.0 30.9 30.6 304 31.7 31.7 Chlorine . . . . . . 8.0 6.1 3 4 2.7 10.0 6 2 6.1 4 4 S d u m hydroxide ... 32.5 30.7 3 4 6 324 80.7 26.4 31.8 27.6 Sodium hydroxide and

chlorinated . . . . . . 16.0 15.8 101 147 248 20.7 23.7 1RO 'None . . . . . . . . . 88.2 38.2 30.8 30.8 30.8 30.8 32.6 324 Sulphuryl chloride . , 3.1 0-7 l % O 9.6 7.6 L.0 0 8 - 0 0 8odIum hydroxide ... 86.0 32.6 34.1 28.6 30.1 27.1 31.2 288 S d n m hydmxlde and

13.0 None . . . . . . . . . 34.6 346 31.2 31.2 36.3 36-3 378 117.9 Sodium hydrolide

dispersion . . . . . . 8.3 6.2 7.6 2.6 6.0 6.1 7 4 8.6

sdum h b i d e and s d n m &droxlde dinpenion . . . . . . 16.0 8.0 11.8 46. 21.4 16.6 304 24.4

sulphuryl obloride ... 187 '12.9 31.6 26.6 30.6 26.8 18.8

Sodium hydmxl@ ... 37.3 32.7 33.2 28.3 34.1 28.1 32.7 21.7

solution at 22.2'~. It seems clear, therefore, that chlorine, sulphuryl chloride, and the sodium hydroxide dispersion make normal wool unshrink- able by promoting disulphide bond breakdown in the surface of the fibres. Confirmation of this conclusion is provided by the following experiments witli fibres treated with potassium cyanide.

(4) Lanthionine Cross-linkages (U ) BORMATION OF LANTHIONINE CROSS-

LlNKAaEs

Although decisive results were obtained with alkali-treated wool, confirmation of the preceding experiments was sought by using flannel treated with potrtssium cyanide, which haa been shown to form lanthionine cross-linkages if the following manuer8O-

When wool is treated with 0.1 M. potassium cyanide for 16.5 hr. a t 66%., conversion of cystine into lanthionine cross-linkages is more complete than with 0.1 N. sodium hydroxide at 22-2"c., and the nature of the cross-linking reaction is more certain. Just as in the cam of alkali treatment, disulphide bond breakdown and linkage-rebuilding proceed side by side, and the cyanide-treated flannel should, therefore, be even more suitable than the alkali- treated flannel for estrtblishing the part played by disulphide bond breakdown in promoting unehrink- ability.

Before proceeding to study the properties of cyanide-treated flannel, the presence of lanthionine cross-linkagee in the fibres was confirmed by super- contraction meesurements. For this purpose, human hair fibres were attached to 2-6-g. patterns of flannel and treated with 260 C.C. of 0.1 M. pottlssium cyanide solution for various times at 66'~. After being washed in running watar for 24 hr., the fibres were boiled in a 6% solution Qf sodium bisulpbite,

R.G*S*R + KCN 3 R*SK + R*SCN -+ R.S.R + KCNS

TABU IX "me of Tr&ment Bupercontractlon

(hr.) (46 ) 0 26.1 1 1.0 2 0.0 3 - 0.3

12 - 0.1 24 0.1

and values for the percentage supercontraction arc given in Table IX.

(b) SHRINKAGE TESTS

A new sample of flannel having the following characteristics waa used in this part of the investi- gation-

Wary ... 33.1 Yorknhire rkeins; 52 en& per In. Weft ... 28.7 YorkaNre skelns; 50 picks per in. weave ... Plain Weight ... 466 0% per scl. yd.

Several 2.5-g. patterns were each treated with 260 C.C. of 0.1 M. potassium cyanide solution for 3 hr. or 24 hr. a t 66"c. f i r being washed in running water overnight, the patterns were pressed between filter paper and conditioned. Both cyanide-tmtd and untreated patterns were then treated witli chlorine, sulphuryl chloride, and potassium hydroxide under the following condi- tions, whioh are slightly different from those used in the preceding sections-

(i) CHLORINE- A O-6Yo instead of a l-Oyo solu- tion of sodium bisulphite was used to remove exmss chlorine from the pattern; otherwise, the conditions were the same as before.

(ii) SULPFIURYL CHLORIDE-By the time this part of the investigation was reached, the important part played by, organic peroxides in the action of sulphuryl chloride on wool had been discoveredP'. In consequence, l.Oyo of oleic acid was added to each pattern from solution in alcohol before treat- ment with sulphuryl chloride in the usual way.

(iii) POTASSIUM HYDROXIDE- Each conditioned pattern was immersed in 100 C.C. of a 0.76% solu- tion of potaseium hydroxide in alcohol containing 3% by volume of water for 36 min. a t 26'0.~~. The pattern was then removed, rinsed in two 100-c.c. Iota of 0.2 M. sulphuric acid for 5 min. each time, and washed in running water overnight.

Milling testa were carried out in the usual way, and the observed shrinkages, which are baaed on the wetted-out areaa of the patterns immediately before milling, are given in Table X.

TABLB X

Treatment

None . . . . . . . . . . . . . . . . . . Chlorine . . . . . . . . . . . . . . . Potassium cyanide . . . . . . . . . . . . Potaesium cyanide and chlorinated ... None . . . . . . . . . . . . . . . . . . Bulphnryl chloride . . . . . . . . . . . . Potaaalum cyanide . . . . . . . . . . . . potaselam cyanide and sulphuryl chlorlde

Percentage Shrinkage in Area

3-hr. 24-lu. Scries Scrien 45.0 44.6 4.7 1.1

22.0 28.8 23.1 29.0

38.1 38.6 3.2 4 4

22.9 26.6 44.0 23.7

42.6 None . . . . . . . . . . . . . . . . . . 4 8 0 . . . . . . 1.i Potaselurn hydroride ... I 16.1 23.0 Potasslum cyanide . . . . . . . . . . . . 280

Potaaplum cyanide and potanalum hydroxide 28.1 21.7

These results are far more conclusive than any obtained in earlier experiments. Neither chlorine, sulphuryl chloride, nor potassium hydroxide is capable of reducing the milling shrinkage of patterns treated with 0.1 M. potassium cyanide for only 3 hr. at 65'0.; and since the action of potas- sium cyanide is to convert disulphide bonds into

sspl. 1949 NOTES. NEW BOOKS AND PUBLICATIONS 463

lanthionine cross-linkages, there can be no doubt that chlorine, sulphuryl chloride, and sodium and potassium hydroxide make normal wool unshrink- able by causing disulphide bond breakdown in the surface of the fibres. TEXTILE CBEMISTRY LABORATORY

DEPARTMENT OF TEXTJLE INDUSTRIES. LEEDS UNIVERSITY

(Received on 8th March 1949)

Reference8 1Speakraen and Goodings. J . T&& Imt., 1926, 17,

Speakman, Tram. Faamday Soc., 1930,26, 61. 3 Wool Industries b a r o h Association, King, and

Speakman, J . Textile Inst., 1941, 32, T 83. kman, Nilssen, and Elliott, Nature, 1938, 142, 1036. :r, all Hicking, and Pentecost, B.P. 463,603;

Hall, this J w m Z , 1939, 55, 389.

T 607.

Galley, B.P. 417,719.

'Elliott and Bpeskman, J.U.B., 1940, p. 641. OHudeOn end AIexander, Fibroue Proteine (Bradford:

8 Neish and Speakman, Nature, 1946, 155, 46. lo Spskmen, B.P. 463,701; this Jour~aul, 1936, 52, 423. 11 Menkart and Speakman, &id., 1947, 63, 322. l a . T o o ~ Broedhurst Lee Co. Ltd., Hall, and Wood, B.P.

Patterson, Gleiger, Mizell, and Harris, Bur. &!mad. J .

Geiger, Kobaysehi, and H d B , *id., 1942, 29, 381. l6 Speakman and Whwell, thia J w r n d , 1936, 52.380. lo Horn, Jonea, and Ringel, J . Bid. Chimi., 1941, 138, 141.

Phillips, Nohure,. 1936, 138, 121. lo Speakman, aid., 1936, 138, 327. lo Phillip, Fibrow Proteins, p. 39. so Cuthberteon and Phillip. BbAem. J. , 1946, 39, 7. 81 Famworth and Speakman, Nature, 1948, 161, 860; this

J d , 1849, 65, 162. la Freney and Lipmn, Nolure, 1940, 145, 26; Council for

Scientifio and Induetrial Research, Australia, Pamphlet No. 94, 1840.

the Sooiety, 1946), p. 193.

638,396.

Rea., 1041, 27, 89.

Notes Proceedings of the Council

At a meeting of the Council, held at the ofEices of the Society, 32-34 Piccadilly, Bradford, on 20th July 1949, the proceedings included the following items of general interest-

Report of the. Leathr Dyes Committee-It waa reported that the editor of the J o u m l of t?w Society of Leather Traded Chemists welcomed the arrange- ment for simultaneous publication of the report in the journals of the two societies.

A88istun.t 8ecretury- The resignation of Mr. K. H. Helm wm reported, and the appointment of Mr. E. Illingworth approved.

&fernberehip- Twenty-three applications for ordinary membership and one for junior member- ehip were' approved.

Meetings of Cotadl and Committees -

Alrgust Neither Council nor any committee of the

Sooiety met during August:

A.G.M. and Dinner 1950 It has been decided that this will be held in

Lee& on Friday, 31st March 1950.

New Books and Publications Die Unterscheidung der Texdlfasern Qualitative und quantitative Anal% von

Faeerstoff-h%ischungen By Bruno Luniak. Second, enlarged edition. Pp.

143 + 288 photomicrographs. Ziirich: Verlag Leemann. 1949. Price, 30 Swiss francs.

This is a second edition of a book which appeared first in 1945. For a second edition of a specialised technical book to be required so soon after the publication of the first edition must be encouraging for the author. To the reviewer it is evidence that the-book has been needed by technologists. This ,particular need is a recent one. As Professor Honegger says in his introduction, the need hse been created by the great increase in the use of man-made fibres. Their many forms and the mixtures in which they are found have created the need for new analytical techniques. The modern man-made fibre is protean in the multiplicity of forms and guises in which it appears. The gamut of size alone ranges over a scale of about 100,OOO : 1, from the coarsest monofils to the finest filaments. The chemical constitutions of these fibres are also very varied and include all those that occur

naturally and many synthetic one8 besides, which do not occur in Nature. When used in the form of staple fibres, often different kinds are mixed with one another and with natural fibres as welI. It is not uncommon to 6nd three or even four Werent fibres preaent in the same yarn. Interesting and attractive textiles are produced in this way, but it presents formidable analytical problems, both qualitative and quantitative. It is to deal with these problems and othem like them that the present book hrt% been written.

In the main the book consists of two distinct parts- there a m 12l.pages of text and 48 pages of photomicrographs. The text begins with an account of q u a h t i v e methods of identifying fibres. Various techniques are described, including staining md microscopical ones. In the text dealing with the latter a few half-tone blocks have been included showing the appearanoea of micro- scopes and acmmrie8. It is always doubtful if it is worth filling book space with manufacturers' illustrations of this type when far more comprehen- siveillustrationsmn beobtained gratis. There would have been justifiaation only if the illustrations