IN THE MAIN, THE CLOTHES THAT WE WEAR, THE BOOKS THAT WE READ, AND THE HOMES THAT WE INHABIT ARE CELLULOSE
C
ELLULOSE iri its varied f o r m has bceu
U? 0. Ueflyw
:I natural arset of oxidation of cellulost~no^ pi,o(l\i(,t,sa nriv surgical gauze t o aid in untold importance in the developniexit of civilization. healing the wounds of war. Prehistoric man used n-ood for light, warmth, and weapons. Cellulose is one of the f e n n : i t u i d polymers. Others are We do not knon when cellulose, in the form of cotton, \vas first starch, rubber, and proteins. Cellulose occurs in a relatively used as cloth. The Gieek historian, Herodotus, described, in 400 pure state in cotton fibers. I t is a n important part of the strucB.c., a flcece- or n-001-bearing tree xxw by travelers iri .-isia. ture of woody tissues of all plants, hut here it, is closely associated Undoubtedly, the cotton plant v a s cultivated much earlicr, for with lignin, pentosans, and other materials. These are difficult rcmiaiii6 of cotton fabric. h a w been une:irtlied in the tombs of t o wniove completely for the purpose of obtaining a pure celluthc' Pharaohs. lwe. This probleni confused and hampered the early investigaMost nat,ural resources are irreplacrablc. Cellulose is unique tors. The purification of rellulose from various plant s o u r c ~ s anioiig the great resources in being replaceable on a short term i a ?till an important field of investigation. basit. :IC cotton, linen, ramie, a n d so forth, or on a longer terni Iiasi> as 11-ood. BEGINNINGS OF RESEARCH Today, the production and utilizatioii of cellulose iiiat(,ri:iIrc*prclsent one of the great sources trf riwtional incornv. In The iiiitiation of research in ccllulose cheniistry is credited t o reality, ceilulore is the basiP riot of on(*industry hut of a coniplc.; -in~clinepayen (8, IO),professor of ".hts e t lI6tiers" in Pari.. intclrrelated group of industrics. Cotton is :i niajor agrirultural Pa>-en'sinvestigations of 1837-42 led him t o the conclusion t h a t product, the 1949 crop being v d u c d i n vxcc~ssof 52,000,000,000 the fibrous constituent of all young plant cells was a carbohydrates composed of g1uco.e residues which had the same clieniical ilSj. But this is 011ly oiie aspect of its iniportaricc. The spiniiiiig, weaving, dyeing, arid garliicsnt t rad-et which could be differentiated from starch by color tests. of beautiful liric~xis. Similarly, a diversified group of industries He ri:rnicd the material c d l u l o s e . It is remarkable that Payer1 are based on Jvood as the raw material. Lumbering, building. Ghoulti h:ive rmchecl these concluzions. His analyses of diffewnt arid n-ooti I':ibric:ttion operations provide incomes for millions of rt~llulosepreparations shon.cd deviations from the proper value^, ' people. In addition, pulps from soft and hard woods ax'thc b arid methods for identifying evpn R Pimple sugar such as glucose for the paper, printing, and puhlishing businesses. were not n-ell advanced. At this time, organic chrniibtry was These vast arras of human activity long preceded organized 1)eginning to emerge a s a uriificd branch of science. 1,iebig had science. Such activities utilized tile physical properties of wood just introduced his analytical methods (1830). Moreover, the or cellulose fibers and hence \\-ere not restrained by any lack of decade coincident with Payen's researches (1830-1840) saw the understanding of the chemistry of cellulose. Though this field introduction of the compound radical theory of Licbig antl devcloped h g e l y on a n empirical basis, science and tec2iiiolog~n'iihler, which led t o the forinul:ition of modrrn structures of rvcre p o w r f u l forces in its growth. €Ion-ever, several industries organic compounds. today o\ve their very existence t o scientific discoveries co~icr~rni~ig Payen's description of crllulosc as a definite chemical vntity the basic chemical reactions of cellulose. These include the did not pass unchallenged. The use of severe chemical tre:itconversion of cellulose into a xanthate whose solutions produce nirnte to separate cellulose from plant tissues often chunged its t,hreads of regenerated cellulose (rayon) or transparent, flexible clieniical and physical pr0pertic.s. liildcr treatments did r u t sheeting. Other chemical operations produce cellulose ethers anti completely remove materials such its lignin, hemicelluloses, :iiitl pentosans. These incomplctely purified ccllulose samples gnv(2 esters, which are utilized for plastics, transparent shreting, fabrics, and lacquers. Prior t o the days of nietal construction, sugars other than glucose upon hytlrolysii, and the c1eine:nt:iry cellulose ester dopes or lacquers conferred the all-important analyses and rtaining ryactioiis cliffertd from those of Payen's cellulose. Inasmuch as the reeidual materials varied acrording tautness t o fabric-covered wings and bodies of early airplanes. The vast motion picture industry is 1itc.rally based on transparent to the original plant tissue used, it was argued that each plant cellulose eater films and owes its inception t o the advent of such produced its ovm particular type of cellulose. Thesc allc~gcd celluloses were designated according t o their plant source +'.p,, films. The growth of the Division of Cellulose Chemistry of t h r "bastose" from jute, and so forth. Cellulose of the conipohition AMERICANCHEMICILSOCIETY was coincident a-ith t'he nioderil growth of coniniercial enterprises based on the chemical properCeH1005, containing only coinbiricd anhydroglucose units, \i-as ties of cellulose and many of the division niembers played imconsidered as a n artificial rrsult of chemical treatments carried far enough to produce the dcsirr-d analytical values and chc>mical portant roles in these developments. properties. Despite increasing competition from other naturitl and s p thetic niitterials, the various forms of cellulose play an ever more The various researches on the unifornlity of cellulose produccd important part in daily living. Shortly after birth, v-e are several valuable results. Schulze differentiated cellulosc from the wrapped in cellulose, we use it in a multitude of ways during life, associated hemicellulose by recognizing t h a t hemicelluloa~ is impress our thoughts on i t for posterity, and we are shrouded in more readily hydrolyzed antl yields sugars other than glucose. it at death. Ironically, cellulose nitrate long ago made possible Pectins were distinguished froin cellulose, and the term "lignin" sn~okelesspowder-a sinew of modern n-arfam-yet chemical was given t o t,he noncarbohydrate portion of the cellulose in-
W. 0. Kenyon, Eastman Kodak Co., Rochester, K. Y. 820
April 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
crustants. Though uxognition of these associated substaiices should have contributed greatlh- to an understanding of the vSriat,ions of properties of the so-called celluloses from different sources, the question of t,hc uniforniity of cellulose was not settled until the early 1920’s. During the controversy over the nature of cellulose, many observations were made regarding its chemical reactions. These firidiiigs led to important commercial developments. The action of nitric acid on cellulose to produce a partially nitrated product which could be formed into clear, flexible, films was discowred by Braconnot in 1833. The more highly nitrated product* iguncottons) were discovered in 1847. At t h a t time, the very significant observation was made t h a t no more than t h e e iiitrnte groups per anhydroglucose unit could be introduced iiito the Inolecule. Treatment, of ccllulose with hot acetic anhydride yielded cellulose acetate (1870 j , and the triacetate n’as i,ecognizcd 3s the most highly acylated product. Invcitipations of the purificat’ion of cellulose had uncovered the dolubilit>- of cellulose in cupraminonium solution and its regencrntion therefrom and t,he action of zinc chloride and sulfuric acid t u parchmentized paper. Very important contributions t o celluloe technology w r e made ill England b y John Mercer. His studics of the action of alkali on cellulose produced the irnproveniciit>in dyeing behavior, luster, and tensile strength rvhich Lec:~nie known technically as “mercer.izatioii.” These pioneer investigat,ions were est,ended by others t o the production of alkali cc,llulo>e used in the preparation of viscose (santhate). celluloce etiiew, : t i i d cert,ain higher cellulose esters. Researches of this period concerning the action of various reagents on wood resulted in the sulfite method for producing wood pulp and the cstat)lishnient u i the sulfate pulp and kraft paper industries. These advunccs in technological and industrial processes ~ v e r eof Eurupe:tii origin. escept, the sulfite process: n-hich was an .American disco\ This, t,hen, was the position of cellulose chemistry and tc’ctinology :it t,he time the ~ M E R I C A NCHEIIICAL SOCIETY c as founded in 1876. During the ensuing ypam u p t o about 1920, great strides ivem made in the industrial use of cellulose, t ~ t hin ;\mcric.a :+nd Europe.
821
This new process-which could use various forms of celluiosr, including wood pulps, as raw materials in addition to the inexpensive chemicals, sodium hydroxide and carbon disulfide-possessed real econoniic advantages. Furthermore, the spinning could be done from water rather than from costly organic solvents. These ntivant.ages w r e soon exploited cornmerc.ially. ;Ilthough the first plants were set u p in Europe, a plant IWS started in the United States in 1910 and was followed rapidly by others. B y the early 1920’5, the xanthate process produced about 75% of the world output of “artificial silk,” while the Chardonnet, and cupramnionium processes shared the reiiiaining market. Iii 1925, the term “rayon” was iiitroduced for this type of filwr. and it has become a hou$ehold word. The use of cellulose nitrate for producing regenerated cellulorca fibers was only one technical application of this versatile ester. Sitration of cellulose t o a high nit,rogen content produced guncottons. Esters of loffer nitrogen contents provided quiiak-
ARTIFICIAL SILK
Though ‘Rbuniur had suggmted in 1754 t h a t a n “artificial silk” niight be produced from varnishes of gums or resins, the iiecesstry materials or processes were not k n o m which would tr:Luslate the idea into fact. I n France, Count Chardonnet uiidertouk i i series of researches which led t o the establishment u f a p1:tiit :it’ BesanGon in 1890 t o produce the first “artificial d k ” ( f . Th? process involved spinning nitrocrlluloae into filameiitc. The dried nitrate filaments were denit,rated by alkali sulfides t o regenerate cellulose filaments. This \vas a dry spinning procebz-i e . , the cellulose nitrate dope was extruded and the wlvents \WIF rcmovcd by air drying. In wet spinning, which \\.:is introduced later, the filaments were coagulated in water. In about 1897, the comniercial production of artificial silk by mut1ic.r process was undertaken in Germany. Ccllulose vias i l u t conwrted t o a derivative, but was dissolved in cupramiiioiiiu~iii;olutions a n d wet,-spun into dilute sulfuric acid coagulating h t l i s , This process v a s based on the studies of Desperssis (?a,IS‘JOI. The English chemists, Cross and Bevan, published man? studies (luring the years 1895-1921 on the properties and reuctiorir ut cellulose. Those dealing irith the action of alkalies on ceilulosc~t o produce “soda cellulose” are of special importance. Soda ccllulose reacts with carbon disulfide t o produce a watersoluble sodium thiocarbonate (xanthate) derivative. Such solutions can be spun into dilute acids, yielding regenerated cellulose filaments. The invention of this process is credited t o Cross, Bevan, and Beadle in 1892 ( I ) . The fibers PO produced w r e first called Viscord and, later, viscose.
Resplendent in his n e w derby, w o r k m a n proudly sports a p a i r of cotton overalls warranted never to rip
822
INDUSTRIAL AND ENGINEERING CHEMISTRY
drying lacquers, while materials of still lower degrces of nitration were combined with camphor, forming plastic compositions of multitudinous uses. The rapid growth of the photographic and motion picture industries during this era demanded increasingly greater amounts of the H? I I H 11 I I 0 0 flexible cellulose nitrate film ('-r-' ('--(.-( I ' < -( base. The automotive indust r y adopted safety glass havI 1 011 OH 011 O H OII kI ing nitrate as the central lamella of the sandwich. Cellulose triacetate, though known for many years, reccivcd little commercial ~ c t t c ~ i r t i c ~ i i . I t was solublr only in a feiv relatively costly organic solvents and gave films or fibers of undesirable physical chnract Tn 1904, Miles patented a process involving the hydrolysis of triacetates t o esters having loiver acetyl contents. These esters, in turn, were soluble in the cheap solvent, acetone. The msulting solutionp, or dopes, became widely used ill World War I t o tauten the canvas coverings of airplanes. The early postwar era saw experiments designed t o use these acetates for fibers arid to replace the relatively unstable cellulose nitrates as filins, sheeting, a n d plastics. Though some encouraging repults Tverc 01)tainpd, the major expansion in the cellulose acetate fic,ld ocruriwl subsequent t o the second decade of t,he cent,ury. These commercial developments required large tonnages ot' cellulose as a chemical raw material. -4fter the long cotton fibers are separated for textile use, there remain the vrry short fibers or linters. Because cotton fibers are essentially celluloer, containing only a very few per cent of waxes and pectin, thc. purification of linters for cheniical use requires relatively simple‘ treatments. On the other hand, v o o d pulp contains associatc~i materials, such as lignin and hemicelluloses. The removal oi these t o produce a high gradr cellulose on a commercial 17 presented a much more formidable probl(~ni. This probleni attacked by many investigators. Although during World W:ir I some sulfite pulp was used, furt.her improvements were necded. I n fact, such research has continued t o the present time. hlany problems concerning tmheuse of cellulose for nonc1ieniic:~l purposes enlisted the attention of incieasing numbers of chemists. The postwar era of the early twent,iesgave t o Americans not only greater incomes h u t increased personal leisure. In turn, the public demanded larger quantities of wood pulp for paper hook stock of ever higher quality. Greater use of color illu. tions in periodicals placed heavier eniphasis upon whiter printing papers. This requirement necessitated improved purification arid bleaching processes for the pulp. The heightened compctition from rayon spurred the research necessary t o improve tho quality of textiles from cotton fibers. Work was directed tov,-ar(I improving the methods used for purifying and hlraching t,he r:iiv cotton, for decreasing shrinkage of cotton goods, decreasing winkling, and improving dyeing qualities. K i t h t,his brief summary, it, will be seen t h a t t h r period or 1875 to about 1920 was prolific with developments in the tcc1inic:ll utilization of cellulose. Cellulose research of this period brought t o light many very interesting observations on the behavior 0 1 cellulose. Unfortunately, the fundamental linon-ledge of thi.: period was not able t o fit these into a coherent picture and rcl:ite t'hem t o the structure of cellulose. This was not the fault of thcx cellulose chemist, for contributory developnients were needed i n the field of physical chemistry and structural organic chemistry. However, from this sea of empirical observation a ferv salient points emerged which proved of prime importance in thc later elucidation of the cellulose structure. .Isindicated earlier, it was long recognized t h a t cellulosc could
Vol. 43, No. 4
v
C'ellulose formula proposed in 1895
he hydrolyzed to give glucosc. Yet, it was not until the classic-:+1 work of E n d Fischer late in the l9t,h century t h a t t,he struct.ure of glucose itself n-as understood. Cotton cellulose was early rliown t o have the struct,ure (C,H,oOs), whereas the empiric:tl formula of t,he glucose is CS€I,,O,. Obviously, these t\ro carhohydrates differ in composition b y one niolecule of water. Recognition of that, fact allowed Tollen? t o propose the ab(JVV formula for cellulose in 1895. Thip formula had the nicrit of intlicating it chain structurc n-ith t'hrcbc avai1:ibie hydroxyl groups for all but the terminal unit ant1 rorrectly indicated the glucose units a s being joined through (.'-O--C links. ;ilthough this formula as in error in indicating the position of the links and in its assunipt,ion of a cyclic acetal qtructurr, it was much nearer the truth than some structurcs 1)roposetl at a much later dat,c. The observations of Franchiniont (1879-1899) showed t h a t , Irolysis, cellulose yields glucose predominantly, while producrs :in acetylattd di- or trisaccharide, later ident>iellot~iosc octaacetatc. Ost had established in 1919
elucidate comthesized it variety of glucose derivatives, particularly the methyl ethprs, as reference compounds for comparison with the degradation products of cellulose. The necessary background work in this field h a d been going on in thc Iahoratories of such carhohydrate chemists, as l'urdie, Irvine, Denham, and Woodhouw. DIVISION OF CELLULOSE CHEMISTRY
Recognizing the need for adequate scientific knonlrdge t.o supplement this extensive technology, a group of chemists reprewnting various interests in cellulose and wood chemistry took the initid steps toward founding a Division of Cellulose Chemistry of thc . h E m c . w C i ~ ~ m c aSOCIETY. r, Did they sense that, the nest t n o decades would n-itncss tlir rapid establishment of the chcniical btructure of cellulose and the adoption of many nmv rwthods for probing thc physical structure of cellulose and \rood? Khcther they did o r not, the g r o x t h of the division coincided n.ith the risc of niodrrn cellulose chemiptry, and the divisional progranis have not only mirrored but have accelerated t h a t a dvn n ce . cellulose syniposiuni \\-as org:inized under the able guithriw of Jasper E. Crane as part of the Division of Industrial :inti 131gincering Chemietry',c program a t the A.C.S. meeting in St. Louis in .ipril 1920. One objective was t o ascertain whrthcr there \vas sufficient interest among chemists to support a cellulose section. The following quotation from the minutes of t h a t symposium indicates the spirit in which this symposium \\-as conceived and in which the Division of Cellulose Chemistry was later founded: T h e object of such a section would be t o promote intercourse
sild cooperation between the chemists in the various C ~ I I U I O W industries. This group constitutes one of the largest and most important of American indust,ries; all branches of i t are intimately concerned in the problems of cellulose, and it seems highly desirable t o promote technical activity in this country along these lines. T h e proposed section n-ould serve as a clearinghouse for pa ers and information on cellulose technology, ant1 should also pray an important, part in pronioting research on the chemistry of cellulose. Sine papers were presented a t this symposium.
Emphasis
was placed on the determination of cellulose in wood and on the
chracteristics of cellulose derivatives, such as the nitrate, acetatc., and phthalate. Al)parently the first symposium was highly successful, for a second one was held a t the Chicago meeting of the A.C.S. in September of that year, again as part of the Division of Industrial :ind Engineering Chemistry. About 200 chemists attended. A coritiuuing emphasis was placed on the constitution of cellulose and its occurrence in plants, while considerable attention was alw directed toIvard the industrial utilization of cellulose from various sources. The interests of the paper maker in this field w e i t indicated by the discussions of the regeneration of book stock and the recover$ of newsprint. Several participants in thesc symposia later played major roles in the founding of the Division of Ckllulose Chemistry, and their scientific contributions ii the field of c e l l u l o ~chemistry won international recognition. At this time, a cellulose section was formed with Harold Hibbert as chairmnn and G. J. Esselen, Jr., as secretary ( 7 ) . The first Cellulose Section was part of the A.C.S. meeting in Rochester, N. Y., in April 1921. The vision and enthusiasm of the founders were well justified, for t x e n t y papers were presented OIL a wide variety of subjects. Wood distillation, cellulose from C O I ~ L W ~ motor P , fuel from vegetation (two papers), the tropical i't~pionsus a source of cellulose, and the role of the chemist in relation t o future liquid fuel supplies were discussed. Thi.ee papers m r e given dealing with cellulose nitrate and two relative to cellulose acetate. One of these latter summarized voluminous data gathered by the Army during World War I concerning the European use of cellulose acetate and celluloae acetate dopes. The Cellulose Section went on record as urging that whatever information on this subject could be made available to the public be placed in the Library of Congress or other suitable library. The niicrostructure of n-ood, lignin tests, standard cellulose, h a t e r furnish reactions, oxidation of cellulose, action of hydrobromic acid on cellulose, hemicellulose, the chemistry of wood decay, and the bleaching and chemical constitution of pulps from coniferous woods were dealt x-ith. Such subject matter ran the gamut from the fundamentals of cellulose structure through various phases of technological utilization. The techniques of microscopy n-ere carefully considered. One of the charter nienibers still recalls a lengthy discussion as to whether the a~iliydroglucoseunit of cellulose contains three or four free hydroxyl group?. I t is bsrticulurly significant that the closely re1ntc.d subjects of lignin and tiemicellulcm structure were disd, and to this day they have continued t o be an import,ant source of papers in the cellulose division. Obviously, the future Division of Ccllulose ChemiPtry was t o include within its interest niany related fields of carbohydrate and plant chemistry. Possibly this complexity of interest has been a potent factor in the grovith and effectiveness of the division through the years. The Rochester program in 1921 brought t o light the dearth of atandard analytical procedures for studying cellulose. The chairniuii appointed G. J. Esselen, Jr., to form n committee t o frame standards t o n-hich all viscosity measurements might be referred. Bjarne Johneen suggested that the section arrange for the preparation of pure cellulose, which could be made available t o investigators in the cellulose field. Use of this standard material in various research programs would facilitate the comparison of results. A committee was appointed t o activate this suggestion. These were the first steps of a continuing program which the
B l u e - e g d . blonde, 8-year-old child picks snowy handfuls oj raw cottori zri Alabania field
The invention of the mechanical cotton picker has greatly speedcd u p the laborious harvesting process 823
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
824
division has fostered through the years for the purpose of standardizing analytical methods and materials. One of thv division's inajor contribution^ t o c e l l u l o ~cheniistry has becn its development of standui~l methods. ('IITI At its April 1922 meeting, the C'i~lluloseSection offered fewer papers than it had the preceding fall. On the other hand, the, growth in the diversity of subject matter was more than evei' apparent. A symposium entitled "Recent Work on the C o w ttitution of Starch and Cellulose" summarized existing structuriil knowledge. The adoption of a repoi? hy the Standard Cellulosc~ Cornniittee establiphcd a niethotl fur prepai,ing :t stantlard form of cotton cellulose. Early in 1922, the section petitioned the officers of A.C.S. for the establishment of n Division of Ccllulose Chemistry. The Cellulose Section niet again in April 1922 antl hecanie a chartered division shortly thereafter. The first meeting of thr Divisioii of C~~llulosc~ C'licni held at Pittsburgh, hi.,iii Septriiiber 1922. The by-] adopted n-ere pubished in the Journal OJ thc Ameri'can Chemical Society in October 1922. The office re: chairman, G. J . Esselrn, Jr.; vice chairman, 1,. E. scwetary-treasurei'. I,. F. Han-ley; executive coniniittee, Id IIibbert and J. F. Wait,. Events of part,icular note mere tn-o symposia, "Thr S a t u r c of Ifrood Cellulosc~,"led 1)y L. E. M k c and E. C. Sherrard, and "Tlie Adsorption of Salts by Cellulose," led by W. D. Bnncroft. Thc former \\-as particularly spirited, and one charter nicmhc,r 17~alIs',that it lasted for a t le 111,. \ T k , I>?. Ychorger, I ) r . Sherrard, l h . Esselen, iiiitl I>r. Slirppard playing proniineiit parts. This occurred o n :I p:rrticularl>- hot day, u-Iwreupon the participants rolled u p thci I , ~Icevesand indulged in a Ivarni but friendly dehate." RENAISSANCE
OF
CELLULOSE CHEMISTRY
Tlicx decade of 1920-1930 may be callctl the renaissance uf cellulow chemistry. Only the major developiiierits can be sketched
('oniplete etherification of cellulose was earlier known to introilurc~t i maxiniuni of three ether groupe in each anhydroglucosch unit. Brilliant experimental work by the English school of carbohydrate chwnists showed that the trimethyl ether can b(, Iiytirolyzed t o a high ~ k l of d 2,3,6-triniethylglucose. Thus, the free hydroxyl groups of cellulose c.orrwpoiid to the 2, 3, and (5 hydroxyls of glucosc~. They further showed that the hydroxyl in position 5 is accounted for hy formation of the pyranose ring of the glucosc unit. This leaves only thcx 1 and 4 hydroxyls to b(, accounted for. Skraup had shown (1901) that acetolysis of cellulose produced cellobiose octaacetate in which two glucose units were joiwd. During 1926-1928, cellobiose wa.8 s h o w to have the nuniber 1 hydroxyl of one glucose unit joined t,o the 4 position of a second glucose unit through an osygen linkage-Le., a 4-glucopyranosyl glucose. I n ietrospect, it would seem that these facts n-ould have justified immediate acceptance of the modern structure of cellulose as shown above. Apparently t,he amylene oxide ring structure and the position5 of the three free hydroxyl groups in the anhydroglucose unit were generally accepted. The issue was how the anhydroglucose unite combined t o form the cellulose niolecule. Two opposing schools of thought arose. One argued t h a t the units were chemically combined into a chain more or less like the presently accepted formula shown above. This concept of a linear cellulose structure was opposed by proponents of the second school, who believed that cellulose was formed by aggrrgation or association of
H
OH
o/
VCI.
C'FT~OII
-c-
\-/H I H 011
J
€I
x
H
1-0'
43, No. 4
011
CHZOH
011
e?itly uccepted formula f o r cellulose rc.lativ~1~. simple carbohydixte units. \.igiion in IW!l m d 1:itc.r 1'ic:tct and his con-orkers (1918-1922] suggested that the gluco~c. niolrrnle formed an internal anhydride having the einpiricnl foriniila C6EI,,0j, corrwponding t o that of cellulose and that this simple anhydride associated to form cellulose. Greeii and ('0workers in the early 1900's follon.ri1 the same line ut' thought but gtivc, :L somewhat different structur:rl formula for the glucose anliytiridc. Hess in 1920 propnuiitlccl the theory that ccllulotc is formed by association of molecrile~of pentaglucii~icioglucose units. Such w i t s were thought to roiitain fire gluwse iiiolr~rules 1:ej v i ~ i c i t lto thr fire hydroxyl groups of : isixth glurore utrit. rit1u:tl viilc~ilceivrces n-ere b f ~ l i r r i ~t od cituse associatioii of their ~ ~ e r ~ t ; i g l u c o ~ i d o g l u cinto o ~ e cc~llulosc. >Ian>- chrniic2tl and phydical consideratioils n-ci'~ brought forward to support this thcory, which attracted man!. :tdhc.rent;. Some of tht' xryuilwnts foi, this association theory v ~ r rdrawn by analogy from the bcti:irior of solutions of cvrt:tin colioitt?, part,icularly soaps3\\-heris thp niolrcules associate into aggrc.g:rtc,s called micellc~. Tod:iy n-e considcr the concept of ii long linear nioli.cul fuiit1:inic~ntaIpart of niir krion-ledge of ILaturnl ~ i u 1d;. polynie~s. In the 1920's, tliis as R novel and dariiig coirctipc. Cnfof,tunately,the iiecc3s:il')' ] ) h y ~ i ( ~methods ~il ~ - e r 6n ~, ~ at t l i a l i c i t o prorc. this linenrity. It C:III xell lie iniaginecl tli:+t tllcsc brcath-t:ikiiig :iilt.uncc,s iii tlic, .qtutlicis of the chenii?tr?- of cc,llulose anti oi its ;trurture c.:iusr.d :I furor iiniong ccllnlosc~ (.I . llenihcrs of thtk developmeiit antl (Iivisiciii follonxd kceiily e:ieh suc f the linear polymer spirited debates 011 t l i c h 11 us those of th(7 :cseoci:rtiiirr theory. Hurold Hibbert, .i,IT.Srhorgc,r, and 1%. LclR. ( :I,:IJ- p ~ i p o ~ (structure3 ~ci for celluloec~ n.tiirli \\-ere based on thr Iin(1:ir polyiiwr concept. In 1921 and 1926, the divisiuii \va5 p:irticularIy honored by the a p p ~ a r a r i r ( ~ O I I its programs of Sir Jamrs Irrine, whose brilliant rejearches had ni:id. E . ] Sheppard [of t,he Eastman liotiak (20.1, Bjarne Johnsen [of Hammermill], L. F. Hawley anti [E. C.! Sherrard [of the Forest Products Laboratory], A. if-. Ychorger [of the C. F. Burgess Laboratory], Gustavus Esselen, antl I were keenly interested in the founding of the division. Thprc, ivcre others, too (like Ilarold -i.Levey of New Orleans and Charles Herty-and still others whom I cannot recall). But I do reniemher how a nuniber of us-at intervals quite apart from thr Sational Meetings of the BCS-met informally a t some coiivenient place (usually a t the Kew York State College of Forestry a t 3yracuse) and after luncheon at the Faculty Club discnsscd the latest developiiierits in the chemistry of cellulose ant1 wood. In those days, the concept of long cellulose chains \vas not gcnerally accepted, and often there were friendly battles involving the interpretation (aiid misinterpretation) of experimental data. Often our round-tahlr discussions lasted all day. KO minutes were ever kept.
-4 resolution of the structural dilemnia was obtained by the acquisition of two nevi types of eyidence. Refercncr. to the structure of cellulose as given a b o w \vi11 show that the linear chains should theoretically he terminated by glucose units which contain four free hydroxyls. In 1932, Han-orth and Machemer demonstrated that about 0.6% of 2,3,4,6-tetramethylglucose was prrwnt in the hydrolysis products of t r i m e t h y l ~ e l l u l o ~ ~
This amount would correspond to H linear chain having possibly 100 t o 200 combined glucose units. The second type of evidence came from experiment,st o deterniiue the struct’ureof thc cellulose by mean!: of .\r-rayF. X-RAY STUDIES
During the decade of 1920-1930, interest was focused niainljon the chemical investigation of the structure of celluloee. The next decade witnessed a shift, of emphasis t o the study of cellulose by various physical techniques. As early as 1923, some European investigators had begun t o use x-rays to etutl!. a wide variety of materiale, particularly cellulosc fibers. The first ptiper on a cellulose diviPion program dealing with this new reswrch tool was presented by &orge L. Clark a t the Detroit meeting in September 102i, undcr the title, “Contribution of );-Ray Science to thr Analysis of the Structure of Cellulose.” The minutes of that meeting indicate t h a t the subject aroused considrrable interest among division members. That x-ray method? could provide the key t o unlock niany secrets of cellulose structure was indicated by the work of the American scientists, Sponsler and Dore. I n 1926, they published the first detailed suggestion for a molecular configuration which conformed n i t h x-ray diffraction data. They conceived a structure for native cellulose consisting of long chains of anhydroglucose rings arranged parallel t o the fiber axis. Unfortunately, t,hese investigators Lvere unable to fit two chain glucoside units int’o their x-ray unit cell without, departing from the accepted 1,4-glucoside linkages and instead substituted a n alternate 1 , l and 1,4 sequence. hIeyer and Mark in their classical publications of 1028 wert. able to fit the 1,4-cellobiose structure of Haworth into the unit cell dimensions obtained previously by Polanyi (1021) and to bring the chemical and x-ray data into accord. The model thus deduced by t h r w investigators still stands essentially rinchanged. Sponsler and Dore presented a critique of the use of x-ray methods in determining thc structure of cellulose fibers a t the division meeting in the spring of 1928. The inipact of thew new concepts on the course of cellulose chemistry is evidenced by the appearance of at least one paper on x-ray studies of cellulose, lignin, or n-ood in most of the sub3equent dirision progrants. These x-ray investigations led t o further speculation on the arrangement of the cellulose chains n-hich formed the fiber. -4theory was developed postulating an oriented aggregation of cellulose molecules into micelles which were arranged like ovrrlapping layers of bricks with t’heir greater dimension along the fiber axis. B e b e e n these niiccllcs was an amorphous bonding substance. This micellar theory accounted for the crystalline :md amorphous patterns obserwd by x-rays. The application of newly developd physical methods sooii rast doubt o n the micellar theory. Staudinger developed :i iluantitative relationship betv-een chain length of polymers and the viscosity of their dilute solutioiis. Viscosity measurrnieiita on cellulose indicated chain lengths many times greater than the lcngth of the nlicelle. Ulhcentrifuge measurements of the .state of dispersion of cellulose in cuprammonium solvent reported by A. J. Stanim a t the spring meeting of 1930 also indicated the prepence of very long polymer chains. L-ltracentrifuge, viscositl-, and osmotic pressure measurenients by E. 0. Kraemer not only confirmed t,he long-chain structure of cellulose but indicated a dist,ribution of lengths. Such data caused a slow metamorphosk from the theory of discrete micelles t o the present theory that the long cellulose chains, though roughly parallel, have areas of tightly packed, highly oriented crystalline structure and areas which ape loosely packed or amorphous. Thus a single chain may extend through adjacent crystalline and amorphous regions. While this present theory seems to explain adequately the chemical and physical
S t a Huntsoille, A l a . ) cotton gin, h u d i c d s of bales wait
to be transported to twills and warehoiiscs
Conmerczal machznery is opcsnftd by coiioti Ircl,riologist at Southern Kogional ticsearch Lahorafor!y..YwOrlcanP. La.
Ezperirncntally treated .fabrics are mxintrd out-of-doors SO that cflecis qf weather arid sunlight can be determined 825
properties of regenerated cellulose materials (and many synthetic polymers), i t niay not be entirely satisfactory when applied to native celluloE fibers. I n the latter case, the morphological structure introduces a complicating factor. MICROSCOPIC STRUCTURE
OF CELLULOSE
The y w r 1035 \vas the approximate mid-point of the division’s history, and the spring meeting at Serr- Tork is still regarded as outstanding. h symposium entitled “Sat,ure of Cellulose and Cellulose F i h r s ” featured comprehensive summations b y authorities in thc then-current. major fields of investigation. Hut :iniong these :ire txr-o papers xr-orthy of special mention. Con,siderablc at trntion had been given recently t o the x-ray structure of cellulose--a realm beyond the limits which could be esplored by the most powerful microscopes. T h e paper by €I. F. Lewis and 0. Smith emphasized the microscopic structure of cellulose in a spectacular fashion. Motion pictures \WE shown of the bir-elling of cotton fibers under the influence of chemical agenk. With proper conditions, the fiber rapidly swelled at intervals along its length until it resembled a string of beads. Then the fiber stmctun: uncoiled, releasing long layers which hiid btrn wound spirally-like a barber pole-along the asis. T h e separated layers then began t o frav, somewhat like the end of‘a rope, into fibrils. These changcs folloxed each other so rapidly t h a t the fiber in its twistings and uncoiling appeared a11mos-t lifelike. M a n y chemists had been thinking o€ cellulose as a chemical formula to be converted into chemical derivatives with iiovel arid useful properties. The comples nmrphology thus demonstrated has continued t o interest the cellulo~echeniists and botanists. Even with the recently added observations of electron rnicroecopy, the structure of cellulose membranes is incompletely known (4j. K.K. Farr, in her paper entitled “Formation of Cellulolle .\Iembranes,” demonstrated by photomicrogmphs t h a t cellulose membranes from various natural sources, including cotton, iippeared t o contain small, uniform ellipsoidal particles. These were postulated a s building units for the cellulose fibrils which formed the ultimate cell wall. Farr distinguished these from t,he submicroscopic micelles previously post,ulated (5). In later pipers, it n‘as suggested t h a t these cellulose particles are held together iii the fiber by a pecticlike material. When the collulose fiber is disintegrated in cupraninionium solutions, the particles remain suspended while the cenlentiiig material dissolves to producc the observed viscosity. Here \vas a startlingly new- idea. Anidc from the botmical mid structural significance of these particles, the c e I l u 1 0 ~chemist had ample rpason t o hrlieve that ccllulose was soluble in cupr:imnioniuni solution and that thu viscosity ol)servml was C ~ toC and a nicmure of-the long polymer chains. .& may \+.ell be iningined, this nca- idea fostered many chemical, microscopic, :ind x-r:iy investigations and d r e x botanists into the diucussion. The Chapcl Hill meeting in .ipril 193’7 ninrked anothrr outsttinding division program, not only because it included a large number of diversified papers b u t also because it climased the C C ~ ~ U lose particle theory discussion. This theory is not now generally :irceptetl. :md a discussion of the experimental evidence is given t.lsenhere ( 6 , 1 2 ) . The period, 1936-1940, saw thr appearance or re-emphasis of severnl new suhj?cts on division programs. Soteworthy were the studies of the formation and properties of cellulose ethers and ccllulosc~act>tatc,as well as the plastic compositions derived from them. Such papers reflected the growing industrial interest in cellulose derivatives. In the field of fundamental rcse:rrch, the papers by .\I. L. Wolfrom and his coworkers on nicrcaptal derivatives of glucose offered a new tool for investigating the hydrolysis structure of simple sugars and cellulose. Invcstigations reported by C. B. Purves et al. introduced new ttXclinicPs for the structural determination of cellulose derivatives. These
Cordura rayon, developed b y Du Pon2 chemists, qoc’s i n f o m a k i n g of cords ,for automobile tires
Researcher examines cotfoti fnhrics, y a m s . and frbers under microscopP a f t w they haiv been chemically treated 826
papers were the forerunners of extensive research by both investigators in their respective fields. SYNTHETIC POLYMERS
During these five years, a remnrkable growth occurred in the field of synthetic polymers. hlany of these synthetics, particularly the vinyl types, were much simpler in chemical constitution than cellulose. They could be prepared b y simple and controllable polymerization reactions and weie free from extraneous materials associated with natural polymers. Because the synthetics are long-chain molecules, they show many physica.1 properties in common with cellulose. These include x-ray pattrrns, ability t o form fibers or sheets, viscosity, osmotic and lightscattering properties, chain 1engt.h distribution, and so forth. A natural result was the development of the science of macromolecules. Pcientiets working in this field dren- freely from the accumulated techniques devked during the physicochemical investigations of cellulose and applied them t o investigations of macromolecules in general. Moreover, the new general concepts t,hus developed werc applird t,o specific problems of cellulose chemistry. This trend became increasingly apparent in thc division programs b e t m e n 1940 and 1945. Papers b y H . Mark a n d coworkers on elastic and plastic behavior of long-chain substances a n d on the fractionation of polymers, a s well a s papers by R . Simha on viscosity properties of chain compounds, by S. Coppick a n d coworkers on the distribution curves of cellulose fractions, by 11. 11.Spurlin on the characterization of cellulose derivatives by solubility properties, and by W. 0. Baker on interchain order and orientation in cellulose esters, opened u p new frontiers. However, the division programs of this era were by 110 m e a ~ i s devoted exclusively t o the new macromolecular concepts. Continued investigations m r e reported in the broad fields of wood and c~llulosestructure, lignin chemistry, t.he isolation and characterization of henlicelluloses and pentosans, a s ~vclia s the efftlcta of chemical treatments upon the properties of rellulozc. Several studies were reported on the oxidation of celluloar, including the experimental work of R. F. Sickerson and his colleagucs, n.ho applied hydrolytic and oxidative methods t o distinguish the amounts of amorphous and crystalline material prewnt. A significant aeries of papers b y hlilton Harris and his coa.orkers on the electrophoretic properties of cellulose and t,heir cation exchange behavior led t o the observations of smtlll amounts of pectin substances associated therein. I n the course of this work, improved methods were developed for estimat,iiig small amounts of uronic acids by carbon dioxide evolution. Paper3 by several workers indicate increasing interest in improving thc physical properties of rayon ya.rns, particularly t o obtain very high tenacity. The riipidly growing technological import:ince of cellulose clcrivatives is s h o ~ nby reports of investigations on thc mc~chanisinuf the formation of cellulose ethers and the distribution of the et,hoxyl groups within the anhydroglucose structure. -4 comprehensive series of papers by C. J. LIalm and C. R. Fordyce and their collaborators described n e v cellulow derivatives, including the trityl ethers and carbamates, cellulose estei, compositions, and in particular new and improved mctliods for thc analysis and characterization of cellulose esters. Tlirpe paptw represent fundamental contributions of import:~ncet o both the science and technology of cellulose derivatives. I3y 19iG the science of macromolecular chemistry had become of intcrest t o scientists in many fields. At the spring meeting. members from the Divisions of Cellulose, Colloid, Organic, Physical and Inorganic, and Rubber Chemistry joined in a High Polymer Forum. This forum, continued through the years, has explored the physical-chemical aspects of cellulose or its derivatives and has considered these substances in terms of general macromolecular theory. As a result, the later cellulose division programs have shifted their emphaPis toward studies of the
E127
Cooked m a s s from kraft digester i s blouw into this tarik ut p u l p niill in Longview, TT-aali.
Experimental paper machine i s operated ut the U . S. Forest Products Laboratory. M a d i s o n , W i s .
I cclitiologic.:~lutilization and c.he~ilic:~l properties of wood, cellulose, ligiiiri, m d rrlatrd materials. Thus far in tracing the history of the division, the accent hi been uii cc~llulose. IIomver, ~iiaiiyprograms featured a large number of papers on related materials, including lignin, pentosans, heniicellulosee, wood structure, and so forth. The division menibers have made many int,ernationally recognized contributions in these fields. I n fact,, certain programs of the division have featured a preponderance of papers on these subject,s over those on cellulose.
LIGNIN AND WOOD
It n.ould be iiiipowihle in t h i j history to trace the coiiiplete developmc~ntof' the cIit,niistry of substaiicea related t o cellulose, particulurly Iigiiiri. .\ brief review will be made of cert,ain high points iii thcse fields a c they appeared on the programs through Cellulose sheets are steeped in caustic soda at x ti~c7iiir~ly difficult to compare the research results of different i!iv(astig:iturs. Ipapel' on the first Cellulose Section program \v:i+ :t di3cussioii b y F:. c'. C'rocker of the significance of the s o - c d k ~ i lignin te*ts. .1 v ~ r ~~j t .~ i ~ t i i iui,rc,i.\.:ition e~it was contained in a paper by 11. l'liilli~js :it the fall niertiiig of 1930, when it was shown tliat :rlktili liyriin produced :i IOM. yield o f 3-(3-niethoxy-4-hydrosypht~iiyljpropane upon (li~tillationivith zinc dust. This appeai.cSc1 t u offtar pi'iiof t h a t ligniii 01 this type contains a certain proportiori of :I coiiibined be~izeneiluck~up. The piwenee of a benzene riiig in lignin n-as Inter confirmed b y the formation of vanillin and :tcetuvanillone by alkaline hydrolysis of lignin sulfonate. I ~ hcafcr., L j b r r s are separated. brzrshcd o u f . andjifibrillntcd 1,atrr studicls reported by E. E, IIarris arid hie coivorkers have so they will enmrsh w h m rriadr info p a p e r shoir-n tliiit the high-tenipc,rature hydrogenation of lignin over suitable catalysts produces cl-clohes?-l propane dcrivatives Tvhich undoubtc~dlyarise by reduction and hydrogen noici coniIiuiients prcsent. Tliri~riglithe years, wrtrrin cc.nters of lignin i ~ t ~ i n g:I:,: exemplified by tlie work of 11. Hibbert arid hi. eoM . O I , ~ C ~ iii P Cauada, G . J. Ititter and E. E. Harris of tiit. Forest Products Lnhoratoq-, aiitl F. E. Urauns, now at t,he 1ii.iitutc OF Paper Cliernist,ry. These ir-orkers contributed a wc-:iltli of c,spi'rimeritail detail on various phases of lignin cheriiistry. 1luch of this \;-(JI,~ \vas presenteti on division prograins particularly :is apiiposia in 1933 and 1948. An outstanding dixusaion of tho lignin prol~lenioccurred a t the Atlantic City meeting in thc f:rll of 19-41, \\-ht.re emphasis IT-asplaced on t h r iso1:itiori Lint1 i i l t ~ i i t i ficatioii C J units ~ which ~(Jlllposedthe lignin molecule. 7'1ir1.~is much t o be d ~ ~ i in i e settling the lignin structure. .I wcent approach 1iaa been the investigation by Alfred Russell of the synthesis of lignin by the condensation or polymerization of 2-hydl.os?.-3-methosy-j-iorn~yl acetophenone. The product obtained has many physical and chemical characteristics paralleling those of lignin from natural sources. However, there is still euiisiderable discussion and disagreement whet'her the product so fornied does have a structure like t h e natural lignin. This new approach has nevertheless stimulated further interest in the Enormous paperma1:ing niaehine in modern plant turns lignin problem. out sheets that are 216 inches wide Research on the structure a n d chemistry of wood has continued a128
throughout the division’s many years. The initial cellulose symposium contained two papers on the determination of cellulose in wood. At, this time, the distillation of Yood v a s of considerable technical importance, and many papers were devoted t o the chemistry and technology of the process, particularly papers by L. F. Hawley and coworkers. The microstructure of brood early attracted the att,ention of cellulose chemists, and the first section meeting contained a discussion of this subject. Later years saw an extensive and continuing study. G. J. Ritter and his colleagues have presented a number of papers dealing with various phases of wood structure. T h e composition and structure of the cell wall of mood, the distribution of lignin in wood, the dissection of wood fibers by chemical means, and the structural unit of wood fibers were particularly emphasized. In 1933, G. J. Ritter and E. F. Kurth introduced the term “holocellulose” to indicate the total carbohydrate fraction of wood freed from lignin and extractives. Subsequent investigations explored the nature of holocellulose from different woods and the hemicelluloses derived from holocellulose. E. C. Sherrard and coworkers specialized in the chemistry and technology of n.ood treat,nients, particularly with respect to the chemical pulping of rrood, hydrolysis of wood, and extractives obtained by various means. I n this connection, if is interesting to note a series of papers by S. I. hronovsky and R. A. Gortner on the pulping of wood, particularly the technological aspects of various chemical treatments. Of considerable technological importance are the investigations of A. J. Stamm on the chemical treatments of wood, particularly with the objective of decreasing mxter permeability and svielling. This by no means covers t,he research Khich was done on wood and wood products during the period of the cellulose division’s history, but is intended to summarize the particular phases which received estensive discussion on thc division programs. It would be presumptuous to attempt to evaluate the importance of the many contributions made b y cellulose division members over the past years. The remarkable increase during the past thirty years in the quality of cellulose products and thc number of nely products introduced attest to the fact that cellulose chemists have done their work well. This period has seen the evolution of improved processes for producing vood pulp, an increase in the strength and wrinkle resistance of cotton fabrics with decrease of shrinkage during use, more extensive use of regenerated fibers and sheeting, the introduction of high-strength rayon cords for automobile tires, improvements in cellulose derivatives, and the introduction of new ones, as well as the adaptation of composition derived from them for a variety of fabric and plastic uses. Progress in the fields of textiles and cellulose plastics have been periodically reviewed in division eymposia. Familiar t o all are new methods and iniprovements in the utilization of wood, particularly as fiberboards, wood Iamin a t w including plywood, and the introduction of trpatments t o decrcxae t,he attack of mold and fungus. 1-anillin for artificinl vanilla extracts and syntlietic molding plastics arc niiide froni the lignin wastes of wood pulp production. The work of Charles Hertp and his colleagues on methods of obt>aininghigh-quality pulp from southern slash pine has been of great tlconomic importance. Papers by L. F. Henderson beginning in 1928 described thc formation of sausage casings from regenerated cellulose. This work led to the large scale production of such casings now widely employed in the meat-packing industry. At one of these early meetings, the division mrnibers engaged in direct personal research on such casings suitably stuffed, cooked, and surrounded by fresh rolls. The opinion was unanimous that cellulose chemistry had beneSted by contact tvith the lomrly hot-dog. Since the beginning of the use of cellulose pulp for paper and cellulose fibers for textiles, a serious problem has been the loss of physical properties caused by the combined action of light,,
Operations are in full swing at sawmill of ihe TT’. T . Smiih L u m b e r Co., C h a p m a n , Ala.
Aerial view of TT‘eyerhaeuser T i m b e r Co.‘s kraft p u l p mill a n d sulfite recovery plant at Longview, ll’ash.
W o o d c h i p s are fed i n t o the tops of these digesters at the start of the p u l p m a k i n g operation 829
Chemical-gradc cotion p u l p leaws drying tunrirl n / Hopewell, T’a., plant of Hercules Powder Co.
>equent#lyproduced additional books particularly relevant t ii newer phases of cellulose chemistry. These books have been of illestimable service to both research Forkers and students. Sfanifestly, it is impossible to mention in this brief history all of the papers given before the Division of Cellulose Chemistry. Thc author has attempted to select certain ones which are illustrative of the growth of cellulose chemistry in the United States. particularly where such papers represent a n extensive series This history would be incomplete without, mention of certain unique characteristics of the division. I t s relatively small size and the closely related scientific interest,s of its members have produced an unusual caniaraderie and opportunity for extensive personal acquaintanceships. The opinions of the youngest and newest niember receive sympathetic attention, while the opinions of the most eminent authority may well be questioned (and often are). I t s vociferous polemics are solely ‘1 %arch for truth. hIay such a spirit long continue. ACKNOWLEDGMENT
moisture, and air t,o produce oxidation resulting in ultimate emAcknowledgnicnt is ni;id(: of the great kindness of many brittlenient. SI;tny chr~tnicaloperations for cellulose purification diiision members, : i n 1 1 ~ y x ~ i a l of l y I,. F. Haivley, H. F. Lewis, encountor this oxidation problem. Witz showed late in the (;. J. Ritter, anti I,. 1,;. \Vise, who have supplied much of the ninetccr.th rcntury (hat this phenomenon was one of oxidation. varly background for tllis history and have critically read portions Siricc that time, many chemof this manuscript’. The ists hare Rtudied the condiauthor appreciates the able Officers of the Division of Cellulose Chemistry, tions under which cellulose ic: ttssistance of C. C. Unruh in 1922-1 951 wscrptil)lr t o oxidation and the compiling of the tables, in have tried to asrertain thc osiproof reading, and in suggesting Year (‘11:tiinian Secreta ry-Treasuw r dative mechanism. ; i very rcsviuions of some of the subject 1922-1 924 G. J . Thselen, Jr. L. F. Hawley extensive litrraturle has derelma t ter in[-luded . 1924-1926 H. 1x13. G r ~ t y I,. F . Hawley oped, and the comprchensiw LITERATURE CITED 1926-1927 I3jninc. ,Johnsen E. C. Shcrrartl work of It;. €Ieusr:r is out1,ouis 1927-1928 E. Wise E. C. Shrrrard (1) Auram, N. H.. “The Rayon standing. A x a result of thc,se Industry,” Ne= York, 1928- 1029 C. J. Stauti J. I,. Parsone studies, the chemists have u. Van Nostraild co., E. C‘. Sherrnrd 1929-1930 J. Stauti learned how to minirnizc the 1927. A detailed account Fl,id Olsen 1930-1931 c. J.Ptaud oxid:ition rc~ictions that acof the history of this inFrcd 01sen .J. L. P:trsons 1931-1932 dustry. company many teciiiiical proc( 2 ) Hrauns, E’. E., “Sature of Harold Ilibtiert 1932-1933 J. L. Parsons c’sses employing c~~llulosc.Rethe Cherriical Compo1933-1 $134 C’. E. Curran w.0. Krnyon cent fundamental stuciicr have nents of K o o d , ” TAPPI H. F. Ipjvis 1934-1 935 W.0. Kenyon provided method? for prt3fc)rcnMonograph Series. No. 6, 1935-1936 G . J . Ititt,rr W.0 . Iienyon pp. 108 et seq., Kew York, tial oxidation of certain parts Technical Association of 1936-1937 Eniil Hcuwr W.0 . Iicnyon of the gluco.w unit in cellulow~ the Pulp and Paper In1937-1938 IT. F. licnricrson W. 0.Iirriyon and h a w identified the proddustry, 1948. 1938-1939 G , I,. Clt1rk W. 0 . Kenyon ucts formed. T h r Ivork of ( 3 ) Farr, FV. K., P a p e r T r a d e J . , SI. I.. TVolfrom 1939-1040 C. R. Fordyce 101, 90 (Sept. 26, 1935). Jackson and Hudson anti later (4) Heuser, E., “Nature of the 1940-194 1 IV. 0. Kenyo11 C. R. Fordyce of Purves and con-orkers on Chemical Components of 1941-1 942 E. E:. Harris C. R. Fordyce periodate oxidation is parWood,” TAPPI AIono€1. JI, Spurlin 1942-1943 C. R. Fordyce ticularly important. Others graph Series, No. 6, pp. C. R. Fordyce E. Bed 1943-1944 12-15, Kew York, Techhave found that nitrogen dinical Association of the J . S. Tinsley C. H. Purree 1944-1946 oside under conditions oxidizes Pulp and Paper Industry, ,J. S. Tinsley SIilton Harris 1946-1947 cellulose gauze to yield a 1948. J . S. Tinsley C. It. Fordycc 1947-1948 product nom employed in (5) Heuser, E., in “Organic W. E. DaviP 11. F. Conalvay 1948-1949 Chemistry,” by H. Gilsurgery as a packing absorh. man, 2nd ed., pp. 1701 J. S.Tinsley FV. E. Davis 1949-1950 able by the body and ac: an et seq., New York, John W.A . Siswri 1950-1951 W .E. Davis aid in the controlling of Wiley & Sons, 1943. bleeding. (6) Hock. C. W., Mark, H.. and Sears, G. R.. i n “Cellulose and Its Derivatives,” by E. Ott, The charter members of t h r division rcsrognized thc need for pp. 306-8, New T o r k . Interscience Publishers, 194X authoritative monographs and textbooks in English on the subJ . Isu. ESG. CHEJI.,12, 940 (1920). jects of cellulose and qood. Discussions of the requirements of R Phillips, 31.,J . W m h . d c r i d . Sci., 30, 65 (1940). brief critical monograph on t,he chemistry of cellulose were initiPurves, C. B.. “Cellulose and Its Derivatives,” hy E. Ott, pp. 119 et s c q . , S e w York. Interscience Publishers, 1943. ated and led by L. E. Wise. Shortly thereafter, the following Reid, J. D., and Dryden, E. C., Tctctile Colorist, 62, 43 (1040). volumes were published: “Wood Distillation” by L. F. Haivley Russell, A , “liature of the Chemical Components of Wood,” (A.C.S. monograph, 1923); “Textbook of Cellulose Chemistry” TAPPI Monograph Series, S o . 6, pp. 220 et seq., h-ew York, by E. Heuser, translated b y C. J. West and G . J . Esselen (1924): Technical Association of the Pulp and Paper Industry. 1948. Sisson, W.A , , i n “Cellulose and Its Derivatives,” by E. Ott, “The Chemistry of Cellulose and Wood” by A. W. Schorger pp. 203 et s e q . , h-ew York, Interscience Pubiishers, 1943. (1926); and “The Chemistry of Wood” by L. F. Hawley and Wise. L. E., private communication to the author. L. E. Wise (-4.C.S. monograph, 1926). Certain of these have “Statistical Abstracts of the United States,” p. 624, Bureau of appeared in revised editions, and other members h a w subCensus, Governinelit Printing Office, Washington. I). C . , 1950.
c.
