Structural design with plastics

Structural design with plastics

Book Reviews Application of nuclear magnetic resonance spectroscopy in organic chemistry (2nd edition) by L. M. JACKMANand S. STERNHELL Pergamon Press...

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Book Reviews Application of nuclear magnetic resonance spectroscopy in organic chemistry (2nd edition) by L. M. JACKMANand S. STERNHELL Pergamon Press, Oxford, 1969, 456 pp, 84s The second edition of this well-known book is a completely new version of the original edition. Professor Jackman has been joined by Dr Sternhell in this task of revision. The book is more than three times as long as the original and contains about thirteen times as many literature references. It appears that the authors have not been well served by their publishers because relatively few references relate to 1966 or later and yet the book was not published until August 1969. The large increase in size has brought about a change in character: the first edition has achieved popularity as a short introductory text (particularly for organic chemists); however, the new version is a full-scale monograph not intended for reading from cover to cover. An important change has been made, the tau chemical shift scale has been abandoned in favour of a delta s c a l e - one in which delta increases positively to low fields. This is likely to be the agreed system for the future. Unfortunately, both editions define this particular delta incorrectly; a sign change has been introduced, possibly because the authors have not realized that frequencies increase towards low fields. Since vs is greater than "TMSequation (1-2-4) should read 3 = (vs -- ~'TMS) × 106/(spectrometer frequency) Luckily, this error does not affect the signs of chemical shifts quoted in the tables. The numbering of equations, tables and diagrams is clumsy due to an unnecessary division of the book into parts as well as chapters. I can see no point in introducing such a complication. Because of the large number of literature references it would have been preferable to put the reference lists at the end of chapters thereby avoiding four-figure superscripts. The organization of subject matter runs as follows: Part l - Introduction to the theory and practice of n.m.r, spectroscopy (54 pages); Part 2 - Theory of chemical shifts in n.m.r, spectroscopy (103 pages); Part 3 - A p p l i c a t i o n s of the chemical shift (109 pages); Part 4 - Spin-spin coupling (87 pages); Part 5 - Applications of time-dependent phenomena (28 pages). There are many good things to be found in this second edition and at such a reasonable price it can be commended to all who are concerned with high resolution n.m.r, spectroscopy. There now remains a gap for a small introductory book similar to the first edition. L. H. SUTCLIFFE

Structural design with plastics by B. S. BENJAMIN Van Nostrand/Reinhold, London, SPE Polymer Science and Engineering Series, 259 pp, £7 The modern trend to the use of plastics in load-bearing engineering structures is clearly of great importance to the plastics industry. Indeed many people in various branches of that industry are looking to this trend, particularly in civil engineering, as a potential large market for plastics. Dr Benjamin's book is an attempt to introduce civil engineers to the potentialities and problems of design with plastics, especially fibre reinforced thermosets, and as such it is very timely. Approximately the first half of the book is devoted to a review of the relevant engineering properties of those plastics which have potential in civil engineering. This is followed by a 339

BOOK REVIEWS brief discussion of sandwich constructions leading into the second half which is a discussion of folded-plate, shell and other structures which the author regards as of special interest for plastics. The appeal throughout is to the practising engineer, emphasis being given to practical engineering aspects. The discussion of materials is essentially a description of properties. There is no discussion of the nature of the materials in either chemical or physical terms (indeed there is not a chemical formula in the book, perhaps a record for books on plastics) and there is no attempt to inform the reader of the existence of the very substantial scientific understanding of properties even by the inclusion of references to suitable texts. The discussion on the behaviour of structures focusses on those which are considered to be of particular application to plastics. The results of the applications of standard classical elasticity theory to these structures are presented and discussed in some detail but the particular problems associated with the special properties of plastics are not explicitly discussed in any significant detail. In places the author makes recommendations on how plastics should be used but neglects to give the appropriate discussion and thus avoids the really cogent problem. This omission is a disappointment but perhaps understandable in the current state of the subject. The author describes some of his own work in designing, constructing and testing various structures in fibre reinforced plastics but does not discuss them in sufficient detail to make the presentation really useful. The reader is left asking a lot of questions, presumably reference to the original papers will provide answers. The book is fairly well presented and is commendably free from typographical errors. The use of space for diagrams is lavish; simple graphs are often allowed to occupy complete pages and data which would best be presented as several lines on one graph frequently appears as several individual graphs making comparisons difficult. Both figures and tables are presented without titles or captions and can only be understood by reference to the relevant portion of the text which may well be several pages away. This will inevitably make reference to the substantial amount of data tedious. A list of symbols and a more careful definition of symbols would be useful. The book will clearly have a greater appeal to the engineer than to the scientist although the latter will find much of interest in the discussion of particular structures. If it is instrumental in bringing engineers to a greater interest in, and appreciation of, plastics it will have succeeded. D. W. SAUNDERS


Polymer V o l u m e 1 l, N u m b e r 4 ( A p r i l ) ' E f f e c t o f s t r u c t u r e o n the glass t r a n s i t i o n t e m p e r a t u r e s o f s o m e p e r f i u o r o a l k y l e n e a r o m a t i c p o l y i m i d e s ' by J. M. B a r t o n a n d J. P. Critchley

Page 21 T h e t w o lines f o l l o w i n g e q u a t i o n (3) s h o u l d r e a d as f o l l o w s : ' w h e r e x a n d y are t h e m o l e f r a c t i o n s o f A a n d B in t h e c o p o l y m e r , a is t h e n u m b e r o f g r o u p s in t h e r e p e a t i n g u n i t a n d TgA~B) ~ TA(B)/ aA (B) '