Degradation of vinyl polymers

Procedures to recover it are now being intensively eval- uated. This is of particular importance to the United States which in 1952 produced only 106,...
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JOURNAL OF CHEMICAL EDUCATION

also reduces the sulfur content of steel so effectively as does addition of manganese. Mare than 14pounds areused to produceone ton of steel, and mast of this added manganese ends up in the slag. Proceduren to recover it are now being intensively evaluated. This is of particular importance to the United States which in 1952 produced only 106,000 metric tons, hut imported 2,140,000 metric tans from India, Africa, Central and South America, Turkey, the Philippines, and Indonesia, Electroplating with manganese is not a familiar art, even though electrowinning of manganese is common practice. Bright coatings can he electrodeposited from aqueous solutions onto steel, aluminum, copper, and zinc. While such coatings impart corrosion resistance because of rapid oxidation a t room tempernture, they soon hecome covered with an unattractive, dark brown film. Manganese a t room temperature is hard and brittle and cannot be worked readily. Alloys of electrolytic manganese with copper, on the other hand, can he worked hot and then quenched without damage. Similar capper alloys with additions of nickel, still maintaining very high manganese contents, can be forged and rolled. Such alloys have not as yet found commercial applieat,ionn. Earh chapter is provided with a very complete bibliography. There are both a table of contents and a n index. The latter seems skimpy in that the alloys listed in the table of contents are not repeated individually in the index. Also, the word "alloys" is misplaced under manganese. I t is surprising t o find in a book published ten years after the close of the Manhattan Project a reference on page 121 to the nonexistant element, "nmsurium." There is nearly as much known about technetium (atomic number 43) as ahout manganese! The aim of the series, "to provide a readable work of reference on the background and the metallurgical, chemical and physical data" of several rarer metals, is being competently realized. These books will find acceptance in e v e q technical lihmry. L h U R E N C E S. FOSTER B ~ M O NM TA . BBACH~B~TTB

DEGRADATION OF MNM. POLYMERS

H. H. G. Jellinek, Senior Lecturer in Physical and Inorganic Chemistry, University of Adelaide, South Australia. Academic Press,Inc., New York, 195% x 329 pp. 123 figs. 51 tables. 15.5 X 23.5 cm. $8.50.

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THEforming of vinyl polymers from simple molecules is n more dramatic occupation than the reverse procedure of hreaking down these fabulously useful materials. However, the degradation of polymer molecules is a n important problem, having both theoretioal and practical interest for the chemist, physicist, and engineer. From the theoretical point of view, a n understanding of degradation kinetics and mechanism improves our knowledge of the basic nature of the original polymer. I t is of practical importance to know the limitations of various polymers in environments in which their use ma." be eontemolated. or oerhaos how to alter the nraoerties of certain

of economic importance in certain cases. "Degradation of Vinyl Polymers" begins with a review of the formal mathematical theories of degradation; this serves as background for the later treatment of the available data. The three principal chapters of the book then deal with degradation of polymers in bulk (in vamzo), in solution and under oxidative conditions, and under the application of mechanical and ultrasonic forces. I n few caqes is there a completely developed picture of the degradation, and the author frequently gives clear statements of what remains to he done, along with suggested methods of attack on the problem. I t is apparent that experimental work in thi.8

field must be designed with unusual care to yield data. capable of significant interpretation. Helpful advice is given by the author for those who would undertake work of this kind. Historical background is well developed, and the author is discriminating in his selection of the most pertinent references for discussion in those areas where the literature is vast. Diagrams of apparatus and graphical presentation of data add greatly to the relative e a e , profit, and pleasure with which this book can be read. Thisreviewer wasparticul.zrlypleased withthe treatment of the question recently posed as to whether polymerizs.tion and degradation may, in certain c a e s a t Least, he facets of a single equilibrium process. Typographical errors, though frequent, are not troublesome.

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MODERN PHYSICS FOR THE ENGINEER

Edited by Louis N. Ridenour, Vice-president, International Telemeter Corporation. McGraw-Hill Book Ca., Inc.. New York. 1954. xi= 499 pp. Many figs. 16 X 23.3 cm. $7.50.

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IT WILL be unfortunate if chemists are inclined to pass this volume by because of its title. I t was chosen by the editar on the assumption that today's physics is tomorrow's engineering. Many chemical educators who have been looking for authoritative reviews of theoretical topics in the areas of physics mast closely related to the subject matter of conventional chemistry courses will be rewarded by the discovery of this volume. The section under the title The Laws o f Nature includes particulsrly interesting chapters on the solid state (Seitz), nuclear structure (Fowler), and elementary particles (Panofsky). The second section, headed Man's Physical Environment, includes easy-reading chapters on astrophysics (Greenstein), geophysics (Griggs) and oceanography (Revelle). The chapter on semiconductor electronics (Bardeen) from the third portion of the volume, entitled Information and its Communication, will also he a. fortunate discovery for those wanting a short, acourate survey of this important suhject that even has raptured the fancy of the popular press. Earh of the 18 ohapters carries a limited hibliography. The volume as a whole is adequately indexed. I t is well illustrated with pertinent plates and dingrnnm, but relxtively few tables of data. WILLIAM F. KIEFFER

DIELECTRIC BMAVIOR AND STRUCTURE

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Charles Phelpa Smyth, Professor of Chemistry, Princeton University. MeGmw-Hill Bwk Co., Inc.. New York, 1955. x 441 pp. Figs. and tables. 17 X 2 4 cm. $9.

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THEREis a suhstanti~lmodern literature on dielectrics, but most of it is written by physicists for physicists. For about 25 years, chemists have depended on Debye's c l a s s i d Baker lectures (1929) and on Smyth's American Chemical Society monograph (1931), supplemented by occasional review papers. The new volume will therefore be universally welcomed by chemists, because i t presents an up-to-date survey of the correlation hetween electrical properties and molecular structure, written by one of the foremost research chemists in the field, who simultaneously is a master of exposition. The hook begins with two ohapters on fundamental theory. It is naturally a matter of personal preference; this reviewer feels that it would have been sounder pedagogy to begin with the Onsager theory and then show that the Clausius-Mosotti equation is a special limiting case of the more general theory, rather than to present the material in its chronological historical sequence.