How hard is hard?

The concept of the micro-mechanical characterisation of polymeric materials may not be familiar to many, despite having enjoyed a steady growth in popularity during the four decades since its first application to these materials. Consequently, the readership of this well-produced text is likely to be quite specialised, but it will include advanced undergraduate and postgraduate students in the areas of materials science and polymer physics. Clearly polymer technologists may also find it useful, particularly in view of the content of the final chapter.

Chapter one gives a brief introduction to the topic and describes the principal tests used to determine the hardness of materials (whether by scratch, indentation or rebound/dynamic methods). Relevant equations and references are provided and the reader's entry to the topic is relatively stress-free.

The second chapter deals more specifically with the detail of the experimental techniques applied to perform the analyses and the manner in which the data is evaluated. Again, the referencing is supportive and photographs and commercial instrument specifications or experimental parameters accompany schematics of the testing apparatus.

The behaviours of both glassy and (semi-) crystalline polymers may differ markedly. Therefore, quite correctly, both families are given separate chapters and there is a brief introduction within each chapter, identifying salient physical features. Thus, for example, the correlation of micro-hardness with glass-transition temperature is discussed in chapter three, while the use of microhardness to determine crystalline transitions is dealt with in chapter four -both with clarity.

The fifth chapter tackles the complex field of multi-component systems: polymer blends, copolymers and composites. The increasing technological importance of multi-component polymer species (and the way in which the introduction of a second species may markedly alter the behaviour of the first) justifies a separate chapter. This is of necessity a rather wider discussion, often encompassing disparate elements, but useful nonetheless. The concept of reversible microhardness is presented in chapter six within a discussion of the effects of strain on sample analysis.

Finally, there is a chapter that emphasises the context in which microhardness analysis is utilised within science and engineering by examining the application of the techniques within the working life of polymer systems (after exposure to weathering, mechanical wear or different processing procedures, and so on). This is a well-judged, interesting choice, since it bridges the gap between purely academic and technological approaches and renders the book of potential interest to a wider readership.

The book is well referenced. Importantly, relevant references have been cited from the past decade.

Ian Hamerton is senior lecturer in organic chemistry, University of Surrey.