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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.
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.
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."
Over two decades ago, !he term characterisation covered just those
techniques which measured the properties of polymers in solution in
order to determine molecular weight and size. The discoveries of
stereoregular polymers and polymer crystals created the need for
new and advanced techniques for characterising chain structures and
bulk properties. Further demands for new and improved
characterisation methods for bulk polymers have resulted from the
recent development and exploitation of multi phase polymeric
systems, such as polymer blends, block and graft copolymers, and
polymer composites. Today, therefore, characterisation is a very
important part of polymer science. The polymer chemist must know
the chain length, chain microstructure and chain conformation of
the polymers he or she has prepared, i. e. the determination of
molecular properties. The scientist involved in exploiting polymers
in such applications as plastics, elastomers, fibres, surface
coatings and adhesives must be informed on the morphology and
physical and mechanical behaviour of his or her products, i. e. the
determination of bulk and surface properties and their dependence
on molecular properties. The techniques required for these
determinations now cover an extremely wide field. Our aim has been
to review a number of techniques critically and in sufficient depth
so that the present state and future potential of each technique
may be judged by the reader. Three criteria were used in the
selection of techniques. First, we wished to present new methods
which have been developed actively in the polymer field during the
past five years.
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