E. E. Dickey
Institute of Paper Chemistry Appleton, Wisconsin
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Teaching- the Chemistry of Cellulose and ~emicellulose
The goal of the academic program of The Institute of Paper Chemistry is to educate men at the graduate level to be scientific generalists. The scientific generalist is presumed to be equipped to combine several disciplines in the solution of scientific or technical problems. Thus, he may use knowledge of chemistry, physics, biology, and chemical engineering in the study of such problems as the relationships which may exist between chemical composition and the behavior of a papermaking pulp. On the other hand, he may be uniquely competent in the investigation of some problem in chemical kinetics, or in the physics of individual fibers under stress. Or he should be able to work in basic research-if his interests lead in that direction. The curriculum of The Institute of Paper Chemistry is largely chemistry and chemical engineering along with substantial classroom and laboratory experiences in physics, mathematics, and biology. A course or two in economics and a language requirement complete the formal instruction. The average per student is about 90 quarter-hours of course work within two academic years. If a minimum cumulative grade has been earned, a MS degree is awarded. No thesis is required for this degree. However, a required six-hour course in the second year may be regarded as our compromise with the more conventional Master's program. The student selects a problem, usually suggested by an instructor who then becomes his supervisor; he works in the library and the laboratory, and finally summarizes the results of his work in a report. The report is available to our staff and students but is not a Presented as part of the Symposium on Education in the Field of Cellulose, Wood, and Fiber Chemistry before the Diviaian of Cellulose, Wood, and Fiber Chemistry and the Division of Chemical Education at the 145th Meeting of the American Chemical Society, New York, N. Y., September, 1963.
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typical Master's thesis. Occasionally the supervisor and the student co-author a publication based on the work. With the Master's degree in hand and otherwise in good standing, the student continues with an individualized program called "Preparation for Research" which usually requires about one academic quarter. If he comes through in good standing, he is passed to doctoral candidacy by the faculty. Then the search for a thesis topic begins. He canvasses his friends, other students, and certain members of the faculty, and finally he makes a written proposal for a thesis topic. This is reviewed by the Committee on Doctoral Thesis, a standing committee of the faculty. If it is judged to he a satisfactory proposal, three advisors are appointed, one is designated chairman, and the work begins. The student writes a progress report and holds a formal progress meeting with his advisors a t least once per quarter. After five quarters have passed, his case is reviewed every term by the Doctoral Thesis Committee in session with his advisors. This serves mainly to make more of the faculty conscious of students who may be slow or in trouble, and to encourage the faculty to help the student toward his goal. Within a year and a half he may complete a thesis which is reviewed and criticized by the advisors. Then a committee, constituted of his advisors and four additional members of the faculty, conducts an oral defense of thesis. Although the advisory committee had little authority, the defense committee renders a judgment to the faculty through the Dean's office. In addition to the academic requirements, he must complete the equivalent of a t least three terms of experience in a pulp or paper mill, or a related industry. Thus, the Institute's program requires approximately four years of study and experience beyond the Bachelor's
degree to complete the development of a scientific generalist with a PhD degree. In the Fall Term, the first-year men review and strengthen their orgauic chemistry with Qualitative Organic (110 credit) and Theoretical Organic, but no deliberate effort is made to emphasize carbohydrates. In the Winter and Spring Quarters, a course in Wood Chemistry includes twenty lectures and 15 to 20 afternoons in the lahorato~yon carbohydrate chemist~y, c~nphasiziug hemicelluloses and cellulose. In the secoud year, some of the men elect a two-hour optioual course in cellulose chemistry; also, certain aspects of the chemist~yof wood polysaccharides are covered in an engiueeriug course which deals with pulping. In all, the total rxpcriences with carbohydrates available in courses involves something less than the equivalent nf seven quarterhours, or lrss than 10% of the cuvrioulum. We begin thc chemistry of carbohydrates by introducing the student to van't Hoff aud I& Rcl and to the concept of the asymmetric carbon atom. The application of these concepts by E. I'ischcr and hZ. A. llosanoff builds the foundation upon which rests the three-dimensional nature of the sugars. We move quickly to the Ilaworth perspective and the Sachse1Iohr conformational perspective formulas which are employed consistently in class presentations. 011the othrr haud, we never hesitate to use the old "miring diagrams" whenever they afford some advantage in representing a fact-evm schematically. At the same t,ime, the studcut is prepared to understand and use the "chair" and "boat" forms as required. The discovery of the agrecmrnt between the absolute configuration of I)-(dextro)-glyceraldehydc and the assumed coufiguration uuder the Fischer-Rosanoff conventions is preacnted. ICventually, the essentials of stereochemistry are awrmed to be in place. Then, some of the classic chemistry of the sugars is summarized with illustrations of mutarotation, epimerization, ascent and descent of the aldose series, selected illustrations of oxidation and of reduction, and the usual listiug of ethers aud esters. The chemistry is not difficult, and most illustrations are drawn with sugars conmonly obtainable from the polysaccharides of wood. We are especially interested i l l Lohy de Bruyn and Alberda von Ekenstein because of thc alkaline pulping of wood, and in the stability of glycosidic bonds to hydrolysis in aqueous acid. Not only is cellulose the simplest and most abundant polysaccharide, hut it is also certainly the most ahundant organic substance available to man. It is not only classic hut easiest of all polysaccharides for preseuting the evidence upon which its structure rests. In the spau of eight lcctures the chemist~yof cellulose aud its I~ehavioras a macromolecule are presented as part of the coursc in Wood Chemistry. For those who may wish more detailed knowledge about cellulose the clcctive course is available. In addition, the molecular and colloidal properties are encountered in courses in physical and colloid chemistry to extend the student's experiences with cellulose. We recognize that there is a considerable gap between our knowledge about the chemical structure of cellulose and that of cellulose as an aggregated high polymer in nat,ural cellulosic fibers. There is a pervading aware-
ness of the need to develop such basic kuomledge, however, if the products of the pulp and paper industry are to be improved systematically. If the organic chemist has pulled ahead of the physical chemist in discovering facts about wood polysaccharides, he is a t the same time aware that a sound organic basis is essential to the physical chemists who would describe more fully the properties of any polysaccharide. So fan, our students seem (to us) well-equipped for the research they undertake. The laboratory experiences begin with mood unless the student has already dealt with it in some undergraduate course. We supply a set of laboratory notes to each student. A sample of wood meal is delignificd, and the resulting holocellulose is separated into hemicelluloses and the residual a-cellulose. The student utilizes these materials to gain experiences in the chemistry of carbohydrates and to become familiar with the components of wood. Students are encouraged to try out ideas of their own and to regard the course as an opportunity to learn as much as possiblc by direct experience about these carbohydrates. Students usually do not want a cookbook or n-ark hook experience, and they quickly respond to suggestions of experiences which are new or novel, especially if the topic has some gelmine relevance to other topics. In addition to the usual equipment of an organic laboratory, they may use specialized equipment in other locatious to run paper chromatograms, viscosities, colorimetric analyses, etc. Recently one student compared chlorite and peracetic acid holocelluloses, another tried the ZemplBn deacetylation on the Blair-Wolfrom compound. Others have tested the interesting effect of temperature on the accessibility of wood hemicelluloses to aqueous alkali. We encourage students to t ~ yany new procedure which comes iuto the literature unless the chemicals or apparatus are too exotic or expensive. One possible test of the student's formalized experiences might be the proportion and type of doctoral research which has been done and is being done in the various areas. In the last ten years The Institute of Paper Chemistry has awarded 83 PhD's. Thirty-four of these had something to do with carbohydrates. Most of them involved the chemistry and properties of polysaccharides: alcoholysis of cellulose; first evidence of glucose-mannose bond; carhoxymethyl cellulose; oxidation of cellulose with X20+ Six of them were studies of monosaccharide chemistry. At present, 30 theses are in progress and 15 involve mainly carbohydrate research. Perhaps this is a disproportionate amount of carbohydrate research, with roughly 10% of the curriculum growing to 4050% of the doctoral research. But carbohydrates are our most important raw material. We have no illusions to share with you on the quantity of facts about the chemistry of carbohydrates of wood which this program lodges in the heads of our students. We believe, however, that their experiences with carbohydrates, minimal though they may be, are adequate foundations on which a doctoral candidate may build the specialized structure of a thesis in hemicelluloses, or some aspect of cellulose chemistry, or in basic carbohydrate chemistry. Volume 41, Number 4, April 1964
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