Developments In Polymer Characterisation 4

This volume includes reviews on tackling polymer characterisation problems and on developing specific characterisation techniques. The first two chapters and the last chapter describe progress in providing character isation information for polymers containing long-chain branching, for polymer blends, and for polymers having preferred orientation. The remaining chapters review progress in individual techniques, showing with examples the characterisation results which may be obtained. It is recognised that the degree of chain branching which can evolve in some polymerisation processes can have a marked effect on the flow properties of a polymer, and therefore on polymer processing behaviour. In the first chapter the characterisation of long-chain branching from measurements of the molecular size and molar mass of a polymer in dilute solution is outlined. It is indicated that a complete characterisation of branching requires the combined use of several techniques, emphasising in particular recent developments involving gel permeation chromatography. Thermal analysis and infrared spectroscopy are widely used techniques in polymer characterisation. Both techniques can provide, very quickly, significant results with readily available instrumentation. This is illustrated by the review of the characterisation of polymer blends by thermal analysis in Chapter 2. An assessment of blend morphology, which influences the behaviour of a material consisting of two or more polymers, is presented in terms of transition temperatures. Conventional infrared spectroscopy involves dispersive spectrometers which do not always provide accurate information on composition and structure for complex polymeric materials.

The policy adopted in Volume 1 of this series of including a relatively small number of topics for detailed review has been continued here. The techniques selected have received considerable attention in recent years. F or this reason and because of the significance of the characterisation data, further coverage of 13C nuclear magnetic resonance spectroscopy and small angle neutron scattering is given in the first two chapters. In Chapter I a large part of the review describes the determination of monomer sequence distributions and configurational sequences in copolymers formed from more than one polymerisable monomer. The review on neutron scattering (Chapter 2) is directed towards the determination of the chain conformation in semi-crystaIIine polymers, which has provided important results for the interpretation of chain folding and morphology in crystaIIisable polymers. Laser Raman spectroscopy has also been used for morphological studies, and this application together with a description of the theoretical and experimental aspects of the technique is given in Chapter 3. X-ray photoelectron spectroscopy because of its extreme sensitivity to surface characteristics has provided information on polymeric solids that could not be obtained by other techniques. The principles and practice of this ESCA technique, including its use for simple elemental analysis, structural elucidation and depth profiling, are described in Chapter 4. The final two chapters are mainly concerned with the chain conformation of polymers in dilute solution. Ultrasonic techniques (Chapter 5) show pmmise for observing the dynamics of conformational changes.

Recent Developments in Polymer Macro, Micro and Nano Blends: Preparation and Characterisation discusses the various types of techniques that are currently used for the characterization of polymer-based macro, micro, and nano blends. It summarizes recent technical research accomplishments, emphasizing a broad range of characterization methods. In addition, the book discusses preparation methods and applications for various types of polymer-based macro, micro, and nano blends. Chapters include thermoplastic-based polymer & nano blends, applications of rubber based and thermoplastic blends, micro/nanostructures polymer blends containing block copolymers, advances in polymer-inorganic hybrids as membrane materials, synthesis of polymer/inorganic hybrids through heterophase polymerizations, nanoporous polymer foams from nanostructured polymer blends, and natural polymeric biodegradable nano blends for protein delivery. Describes the techniques pertaining to a kind (or small number) of blends, showing specific examples of their applications Covers micro, macro, and nano polymer blends Contains contributions from leading experts in the field