Basic Science in the Literature of Plastics - ACS Publications

Considering basic science in the general field of plastics there are .... service should not be longer than four or five lines and should essentially ...
0 downloads 0 Views 938KB Size
Basic Science in the Literature of Plastics H. F. MARK, Brooklyn Polytechnic Institute, Brooklyn 2, Ν. Y.

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

E. S. PROSKAUER, Interscience Publishers, Inc., New York 1, Ν. Y.

Basic science in the general field of macromolecules includes the principles of their synthesis, the investiga­ tion of the size and structure of individual molecules in solution, and the relationship between structure and properties in the bulk phase. Approximately 450 scientists in 90 laboratories all over the world devote the major portion of their time to basic science in the subject field. The results of their work are pub­ lished in about 150 technical journals which include literature on plastics. Reviewing the literature at present is difficult. The author suggests services which include a weekly news letter, monthly journal for papers, semiannual journal for review articles, and formula and data sheets in addition to regularly ap­ pearing monographs, textbooks, and handbooks.

Considering basic science in the general field of plastics there are essentially three divi­ sions—synthesis, molecular structure, and structure and properties of bulk polymers.

Definition of the Field Synthesis of macromolecules which are of interest and importance for the production of plastics comprises mainly the mechanism of polymerization and polycondensation, the use of various techniques such as polymerization in bulk solution, suspension, emulsion, in the gas phase, in the gel phase, and on interfaces. It also includes the appli­ cation of different types of catalysts, initiators, activators, promotors, modifiers, retarders, and inhibitors; and the phenomena of copolymerization including "graft" and "block" copolymerization and second-stage cross linking. It comprises studies on the degradation of macromolecules by heat, light, chemical reagents, mechanical action, and micro-organisms and the fundamental aspects of the methods of counteracting these de­ teriorating influences. Molecular structures of macromolecules are revealed by experiments carried out in the dissolved state. A large class of contributions of this kind deals with the elucida­ tion of details in the molecular structure by organic chemical methods, such as the estab­ lishment of head-to-tail or head-to-head, tail-to-tail sequence, cis-trans isomerism of double bonds in the chain, existence and structure of cyclic systems, analytical deter­ minations of end groups, and the study of the chemical composition of copolymers. Another equally large and significant group of studies is concerned with the physicochemical behavior of macromolecules in solution, their molecular weight, molecular weight distribution, solubility, fractional precipitation and specific intermolecular aggregation in certain solvents as elucidated by the measurements of osmotic pressure, light scattering, sedimentation, diffusion, and electrophoresis. It also comprises the phenomena of vis­ cosity and flow birefringence in solutions of macromolecules and their evaluation in terms of structural details of the solute. 122

LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

MARK AND PROSKAUER—BASIC

123

SCIENCE IN THE LITERATURE O F PLASTICS

Investigation of the structure and properties of polymers in the bulk phase includes many important papers describing the use of x-ray and electron diffraction, ultraviolet and infrared absorption, and microwave spectroscopy to establish the degree of crystallinity and the orientation of the crystalline domains i n a given sample as the consequence of mechanical deformation such as stretching, rolling, or extruding. Other articles deal with the rheology of polymer melts or of concentrated macromolecular solutions; again others focus their attention on the mechanical, electrical, and optical properties of plastics dependent on the molecular structure, the temperature, and the presence of auxiliary materials such as softeners, plasticizers, antistatic agents, and reinforcing fillers. Phenom­ ena such as adhesion, cohesion, plasticity, brittleness, abrasion resistance, electrical resistivity, and optical refractivity belong to this group and are of considerable impor­ tance for practical problems i n plastics application. A l l publications containing information of these types fall into the subject field of literature on the basic science of plastics if they deal with macromolecules important for the synthesis of plastics or if they describe methods which could be applied to such m a ­ terials. Evidently a new method of measuring molecular weight or of fractionating a macromolecular system is of interest even if i t has not been applied to technologically useful material. Papers which contain only qualitative or general remarks connected with fundamental work on macromolecules have been omitted but, i n general, i n case of doubt, borderline publications have been included because i t was felt that i t would be a smaller mistake to have a few articles of lesser significance included than to have something really important missing.

Origin of Information A l l experimental methods and data, a l l compilations and correlations, and a l l theo­ retical interpretations emerge from a number of laboratories i n which scientists devote their efforts to work on basic science i n the general field of macromolecules. The C o m ­ mission on Macromolecules of the International Union of Pure and Applied Chemistry is just now completing a world-wide survey of such laboratories as to their location, number of scientific and technical workers, equipment, field of special interests, and yearly scientific output. The tables i n this paper are part of this survey, which will be presented i n full at the meeting of the International U n i o n i n July 1953, i n Stockholm. Table I.

Australia Austria Belgium Canada England France Germany Hungary India Israel

Laboratories Engaged in Basic Work on Macromoiecules No. of Laboratories

No. of Workers

2 3 3 4 12 4 8

10 10 15 20 60 20 60

3 1

io5

No. of Laboratories Italy Japan Netherlands Russia Scandinavia Slavic Countries South America Spain Switzerland United States

No. of Workers

2 3 5

10 10 20



20

"2 1 5 25

5 5 20 150

It appears that about 90 laboratories with a total of 450 scientists are devoting the major part of their time to expanding the knowledge i n the field of basic science of macromole­ cules. Table I lists the number of laboratories and number of workers i n each laboratory according to geographic distribution. L a c k of information made i t impossible to fill i n definitive data for Hungary, Russia, and the Slavic countries (Czechoslovakia, Poland, Romania, and Yugoslavia) but it is fair to assume that there are about 10 to 15 labora­ tories i n these countries. I n order to show how the number of workers who spend es­ sentially all of their time i n the subject field was estimated, Table I I is added, which con­ tains the estimated number of workers i n a few well-known laboratories that for many years have been making regular contributions to fundamental research i n the plastics field. Of course, the total number of scientific and technical employees i n these organizations is much larger than the figure given i n Table I I , but most of them work either preponderLITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

ADVANCES IN CHEMISTRY SERIES

124

antly on practical problems or on basic science not directly connected with the preparation, properties, and application of plastic materials. I t is probably fair to estimate that 80 to 8 5 % of all new results and ideas on basic science i n the plastics field emerge from the laboratories listed i n Table I . There are, of course, outsiders who do not work i n d i ­ rect connection with any of them and who contribute significant new material, but their number and location vary too much to be assessed i n a reliable way i n this preliminary survey.

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

Quantity and Distribution of Information As soon as work on a certain problem i n the laboratories has reached a sufficiently advanced stage, the authors will want to make their results known. The first step is to present a paper at one of the many scientific meetings, which are held i n a more or less regular manner all over the world. It appears that more than 8 0 % of all new facts and ideas are first presented orally and only later appear as printed papers. For anyone who is interested in current developments, a quick and regular report on the events at the scien­ tific meetings will be of special interest. A survey on the number, character, and size of congresses i n the various countries led to Table I I I , which contains the number of large Table II.

Some Important Laboratories with Number of Workers in Macromolecule Field National Bureau of Standards, Washington, D . C. Harvard University, Cambridge, Mass. Du Pont Experimental Station, Wilmington, Del. Dow Chemical Co., Midland, Mich. University of Manchester, England Research Laboratory of the ICI, Welwyn Garden City, England University of Strasbourg, France University of Freiburg, Germany Research Laboratory of the B A S F , Ludwigshafen, Germany University of Basel, Switzerland

8 5 12 5 6 4 5 4 7 4

scientific meetings held i n the specified area at which papers on fundamental research in the polymer field were presented and discussed, together with the number of these papers and an estimated figure on total average attendance. I n the case of the 122nd meeting of the AMERICAN CHEMICAL SOCIETY it was evident that such a large congress could not be counted as a single event. Considering the program of the various divisions, it was felt that this meeting was equivalent to six separate conferences presenting new information i n the subject field because the Divisions of Cellulose Chemistry, Colloid Chemistry, Organic Chemistry, Paint, Varnish and Plastics Chemistry, Physical and Inorganic Chemistry, and Polymer Chemistry each had a number of papers contrib­ uting to basic science i n the subject field. The number of these papers was about 100, and the total number of chemists who attended the sessions was probably 2500 to 3000. Comparing the total number of papers presented i n 1951 (1200 to 1300) with the total number of scientists working i n the field (450 to 500), it was concluded that, on the average, each producing worker reports between two and three times a year on the results of his investigations. This is a proportion which seems to agree well with the actual conditions. Table III.

Conferences and Meetings (Above 100 attendants)

1949 Meetings Papers presented Chemists attending

40 400 8000

Western Hemisphere Ï95Ô 1951 50 450 10,000

60 650 15,000

Europe, Asia, and Australia Î949 1950 Ï95Ï ... ... ...

32 400 4000

35 600 6000

The next step i n the dissemination of new results is*to publish them i n one of the technical journals which regularly carry articles i n the general field of macromolecules. Table I V gives the number of such journals published i n the various countries; their LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

MARK AND

Table IV.

PROSKAUER—BASIC SCIENCE IN THE LITERATURE OF

PLASTICS

Journals, Published in Various Countries, Containing Papers in the General Field of Macromolecules Papers Appear Two or more Regularly in each issue

Australia Austria Belgium Canada England France Germany Hungary India Israel

3 6 4 4 11 6 18 2 4 2

0 2 2 1 6 3 7 0 0 1

Papers Appear Two or more Regularly in each issue Italy Japan Netherlands Russia Scandinavia Slavic Countries South America Spain Switzerland United States Total

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

125

5 4 4 6 10 8 5 2 4 35

2 2 2 4 2 0 0 0 1 10

143

45

total is about 150. This is a very large number to review, and it is therefore important to determine how much useful material the individual journals carry. Therefore essential journals—those which publish i n every issue at least two articles containing new infor­ mation on basic science i n the polymer field—were selected. The numbers of these jour­ nals with originating countries is listed in Table I V . A list of the essential journals is given i n Table V , and a list of lesser known journals occasionally containing scientific articles on plastics is presented i n Table V I . Table V I I shows the total number of publica­ tions on fundamental research i n the plastics field for the past three years, specified as original articles, review articles, and comprehensive books. The number approaches 1000 per year, which indicates that every active worker i n the field publishes, on the average, about two papers per year.

Services to Facilitate Literature Reviewing In considering an adequate way to reach the existing information, one might pro­ pose the following set of services : News Letter, a weekly, containing, i n condensed form, the announcement of new work done and new results obtained. The individual items of this advanced information service should not be longer than four or five lines and should essentially cover a l l Table V.

Selection of Journals Containing Two or More Papers on Macromolecules in Each Issue England Chemistry and Industry Journal of the Chemical Society (London) J ournal of the Textile Institute Nature Proceedings of the Royal Society (London) Transactions of the Faraday Society (London) France Annales de chimie (Paris) Bulletin de la société chimique de France Comptes rendus hebdomadaires des séances de l'académie des sciences German Angewandte Chemie Annalen der Chemie, Justus Liebigs Chemische Berichte (Berichte der deutschen chemischen Gesellschaft) Makromolekulare Chemie Zeitschrift fur Elektrochemie und angewandte physikalische Chemie Zeitschrift fur Naturforschung Zeitschrift fur physikalische Chemie Russia Doklady Akad. Nauk S.S.S.R. Isvest. Akad. Nauk S.S.S.R. Journal of Applied Chemistry (U.S.S.R.) (Zhurnal Prikladnoï Khimii) Journal of General Chemistry (U.S.S.R.) (Zhurnal Obshchel Khimii) United States Industrial and Engineering Chemistry Journal of the American Chemical Society Journal of Applied Physics J ournal of Chemical Physics Journal of Colloid Science Journal of Physical Chemistry Journal of Polymer Science Science Tappi Textile Research Journal

LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

126

A D V A N C E S IN

CHEMISTRY SERIES

lectures given at scientific meetings immediately after they have been delivered, and letters to the editors of the essential journals when they deal with basic science in the plastics field. According to Table I I I about 1200 individual news items will be available per year; therefore about 25 items will appear in each weekly issue of the news letter. With an average length of five lines for each item, it follows that the news will consists of four pages per issue and can therefore be distributed easily and con­ veniently scanned even by very busy people. Information services of this type are com­ mon in technical and industrial fields. Chemical and Engineering News carries many Table VI.

Lesser Known Journals Containing Papers on Plastics

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

Australian Journal of Avplied Science Bulletin of the Research Council of Israel Busseiron Kenkyu Gazetta chimica italiana Materials & Methods

MetaUurgia Physica Svensk Kemisk Tidskrift Zeitschrift fur analytische Chemie Zhurnal Fizicheskoi Khimii

announcements of this character for the entire field of chemistry, whereas Rayon Organon and Natural Rubber News cover the more specialized fiolds of production, consumption, and technical progress in rayon and natural rubber. The news service proposed here would be focused exclusively on fundamental research i n the polymer field. In order to illustrate the type of condensed information which this service should offer a few sample items on lectures and on articles which appeared i n the spring of 1952 are presented. These ap­ peared in lesser known journals, so they could be considered as being difficultly available information. R . S. R i v l i n and D . W . Saunders, British Rubber P r o d . Res. Ass.; Trans. Faraday Soc, 4 8 , 200 (1952). Free energy of deformation for cured rubbers. Load-deformation data on vulcanization covering a wide range of hardness are reported. The mean segment lengths as determined from swelling can be correlated with the deformation data. C. Pinte, P . Rochas, and J . Henno, Centre Rech. Ind. Text., Bull. inst. textile France, 30, 141 (1952). Influence of stretching on the structure of swollen cellulose xanthate gels. X - r a y diffraction and swelling measurements are used to study the molecular structure of cellulose fibers at different degrees of stretching. B . G . Ranby, Inst. Phys. Chem., U n i v . Uppsala, Arkiv Kemi, 4 , 241 (1952). Fine structure and reactions of native cellulose. Electron microscope study of morphology of celluloses from wood, cotton, bacteria, tunicates, and algae; behavior of samples on swelling i n sodium hydroxide and hydrolytic degradation. E . Treiber, G . Porod, and W . Lang, University Graz, Austria, Osterr. Chem. Ztg., 53, 162 (1952). On the existence of orthoxanthates. Spectroscopic, ebullioscopic, and ana­ lytical data on isopropylxanthate indicate that there exists no ortho form of the xanthates of this alcohol. It is concluded that the less stable xanthates of cellujose cannot be explained by ortho-xanthate formation. Standard Journal, appearing semimonthly and containing original articles, short notes, and letters to the editor. W i t h 500 papers per year such a journal could take care of about 5 0 % of all articles and would represent a considerable concentration of information. Right now two magazines exist that are exclusively devoted to papers on basic science i n the polymer field: the Journal of Polymer Science and Makromolekulare Chemie. Together they have about 1600 pages per year and contain about 18% of all articles written i n the field. Table VII.

Total Number of Publications on Plastics

T y p e of P u b l i c a t i o n

1949

1950

1951

O r i g i n a l articles R e v i e w articles Comprehensive books

750 45 14

810 51 10

890 56 16

Review Magazine, appearing quarterly and containing only review articles. Planning 400 pages per year it could publish 10 review articles i n each issue and could take care adequately of the condensation, documentation, and correlation of new LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

MARK AND PROSKAUER—BASIC SCIENCE IN THE LITERATURE OF PLASTICS

127

results in the subject field. This magazine would be very similar in character to Chemical Reviews or Quarterly Reviews. Formulas and Data Sheets, issued yearly, containing all newly established fundamental equations and numerical data on basic properties of polymers. These would include new equations to express viscosity as a function of temperature, concentration, or shear rate; new relations between intrinsic viscosity and molecular weight; new for­ mulas on the kinetics of polymerization and copolymerization; data on second-order transition points of new polymers or copolymers; heat and entropy of solution, dilution, melting, and swelling of macromolecules; and similar fundamental data as they are con­ tained in the articles appearing during the reference year. They would be similar in purpose to the Technical Data Sheets and complement them in regard to fundamental information. In addition there will be monographs, textbooks, and handbooks written by special­ ists in the field as the progress in polymer science and the demand for comprehensive documentation and information justify their publication. The ideal system of information in the subject field presents only two new features, the news letter and the data sheets. They do not exist as yet in the domain of basic science on plastics and would probably assist the individual worker in the field to find existing information and to keep the permanent and significant results of the scientific progress on file. Bibliography GENERAL

Bawn, C. Ε. H., "Chemistry of High Polymers," New York, Interscience Publishers, 1948. Burk, R. E., and Grummitt, O., ed., Frontiers in Chem., 6, 1949. High Molecular Weight Organic Compounds. Ellis, Carleton, "Chemistry of Synthetic Resins," New York, Reinhold Publishing Corp., 1935. Fowler, R. H., and Guggenheim, Ε. Α., "Statistical Thermodynamics," New York, Macmillan Co., 1940. Frith, Ε. M., and Tuckett, R. F., "Linear Polymers," New York, Longmans, Green, and Co., 1951. Houwink, R., ed., "Elastomers and Plastomers. Their Chemistry, Physics, and Technology." Vol. I, New York, Elsevier Publishing Co., 1950. Lamb, H., "Hydrodynamics," 6th ed., London, Cambridge University Press, 1932. Mark, H. F., Proskauer, E. S., Doty, P. M., Frilette, V. J., and Zimm, Β. H., "Science of Plas­ tics," New York, Interscience Publishers, 1947. Mark, H. F., and Tobolsky, Α. V., "Physical Chemistry of High Polymeric Systems," 2nd ed., New York, Interscience Publishers, 1950. Meyer, Κ. H., "Natural and Synthetic High Polymers," 2nd ed., New York, Interscience Publishers, 1950. Morrell, R. S., and Lanton, H. M., "Synthetic Resins and Allied Plastics," New York, Oxford University Press, 1951. Penn, W. S., "High Polymeric Chemistry," London, Chapman and Hall, 1949. Ritchie, P. D., "Chemistry of Plastics and High Polymers," New York, Interscience Publishers, 1949. Robinson, Η. Α., ed., "High Polymer Physics," New York, Chemical Publishing Co., 1948. Schack, W., "Manual of Plastics and Resins in Encyclopedia Form," New York, Chemical Publishing Co., 1950. Schmidt, Α. X., and Marlies, C. Α., "Principles of High-Polymer Theory and Practice," New York, McGraw-Hill Book Co., 1948. Seitz, F., "Modern Theory of Solids," New York, McGraw-Hill Book Co., 1940. Staudinger, H., "Der Aufbau der hochmolekularen organischen Verbindungen-Kautschuk und Cellulose," Berlin, Hirschwaldsche Buchhandlung, 1932. Stuart, Η. Α., ed., "Die Physik der Hochpolymeren. Vol. I. Die Structure des freien Mole­ küls," Berlin, Julius Springer, 1952. Timoshenko, S., "Theory of Elastic Stability," New York, McGraw-Hill Book Co., 1936. Tolman, R. C., "Principles of Statistical Mechanics," Oxford, Oxford University Press, 1939,

MECHANICAL AND PHYSICIAL PROPERTIES

Alfrey, T., Jr., "Mechanical Behavior of High Polymers," New York, Interscience Publishers, 1948. Blom, Α. V., "Organic Coating in Theory and Practice," New York, Elsevier Publishing Co., 1951. Burgers, J. M., Hermans, J. J., and Scott Blair, G. W., ed., "Deformation and Flow," Vol. I, "Deformation and Flow in Biological Systems," by A. Frey-Wyssling, New York, Inter­ science Publishers, 1952. LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.

128

ADVANCES IN CHEMISTRY SERIES DeBruyne, Ν. Α., and Houwink, R., "Adhesion and Adhesives," New York, Elsevier Publishing Co., 1951. Durrans, T. H., "Solvents," 6th ed., New York, D. Van Nostrand Co., 1950. Gnamm, Helmut, "Die Lösungsmittel und Weichmachungsmittel," Munich, Karl Hauser Verlag, 1950. Green, H., "Industrial Rheology and Rheological Structures," New York, John Wiley and Sons, 1949. Haward, R. N., "Strength of Plastics and Glass," New York, Interscience Publishers, 1949. Kunin, Robert, and Meyers, R. J., "Ion Exchange Resins," New York, John Wiley and Sons, 1950. Mellan, I., "Industrial Solvents," New York, Reinhold Publishing Corp., 1950. Reiner, M., "Deformation and Flow," New York, Interscience Publishers, 1949. Reiner, M., "Twelve Lectures on Theoretical Theology," New York, Interscience Publishers, 1950. "Structural Adhesives. Theory and Practice of Gluing with Synthetic Resins," London, Lange, Maxwell, and Springer, 1951.

Downloaded by CORNELL UNIV on June 2, 2017 | http://pubs.acs.org Publication Date: June 17, 1954 | doi: 10.1021/ba-1954-0010.ch014

POLYMERIZATION

Alfrey, T., Jr., Bohrer, J. J., and Mark, H. F., "Copolymerization," New York, Interscience Publishers, 1952. D'Alelio, S. F., "Fundamental Principles of Polymerization," New York, John Wiley and Sons, 1952. Küchler, L., "Polymerisationskinetik," Berlin, Julius Springer, 1951. Mark, H. F., and Raff, R., "High Polymeric Reactions," New York, Interscience Publishers, Inc., 1952.

SPECIAL SYSTEMS

Blout, E. R., and Mark, H. F., ed., "Monomers," New York, Interscience Publishers, 1951. Brauns, F. E., "Chemistry of Lignin," New York, Academic Press, 1952. Carswell, T. S., "Phenoplasts," New York, Interscience Publishers, 1947. Flett, L. H., and Gardner, W. H., "Maleic Anhydride Derivatives," New York, John Wiley and Sons, 1952. Götze, Kurt, "Chemiefasern nach dem Viskoseverfahren—Reyon und Zellwolle," 2nd ed., Berlin, Julius Springer, 1951. Haszeldine, R. N., and Sharpe, A. G., "Fluorine and Its Compounds," New York, John Wiley and Sons, 1951. Hermans, P. H., "Physics and Chemistry of Cellulose Fibers," New York, Elsevier Publishing Co., 1949. Hultzsch, K., "Chemie der Phenolharze," Berlin, Julius Springer, 1950. Kainer, Franz, "Polyvinylchlorid und Vinylchlorid-Mischpolymerisate," Berlin, Julius Springer, 1951. Ott, Emil, and Spurlin, Henry, ed., "Cellulose and Cellulose Derivatives,". New York, Interscience Publishers, 1943. (2nd ed. in preparation.) Post, H. W., "Silicones and Other Organic Silicon Compounds," New York, Reinhold Publishing Corp., 1949. Pummerer, R., "Chemische Textilfasern und Folien," Stuttgart, Ferdinand Enke Verlag, 1951. Reppe, W., "Neue Entwicklungen auf dem Gebiete der Chemie des Acetylens und Kohlen-oxyde," New York, Walter J. Johnson, 1949. Rochow, E. G.. "Chemistry of the Silicones," New York, John Wiley and Sons, 1946. Schildknecht, C. E., "Vinyl and Related Polymers," New York, John Wiley and Sons, 1952. Simonds, J. H., "Fluorine Chemistry," Vol. I, New York, Academic Press, 1950. Sutermeister, E., and Browne, F. L., "Casein and Its Industrial Applications," New York, Reinhold Publishing Corp., 1939. Vale, C. P., "Aminoplastics," New York, Interscience Publishers, 1950. Ward, A. L., and Roberts, W. J., "Styrene," New York, Interscience Publishers, 1951. Warth, A. H., "Chemistry and Technology of Waxes," New York, Reinhold Publishing Corp., 1947.

RECEIVED October 31, 1952. Presented before the Division of Chemical Literature, Symposium on Literature of Synthetic Resins and Plastics, at the 122nd Meeting of the AMERICAN CHEMICAL SOCIETY, Atlantic City, N. J.

LITERATURE RESOURCES Advances in Chemistry; American Chemical Society: Washington, DC, 1954.