Elsevier

Polymer

Volume 48, Issue 1, 5 January 2007, Pages 2-18
Polymer

Feature Article
Deformation mechanisms in polymer fibres and nanocomposites

https://doi.org/10.1016/j.polymer.2006.11.016Get rights and content
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Abstract

This review covers the development of the understanding of the deformation micromechanics of both synthetic and natural polymeric fibres using spectroscopic and X-ray diffraction techniques. The concept of fibres as composites, where hard and stiff phases are combined with softer polymeric materials is also discussed. Starting with the first discoveries on the molecular orientation and morphology of polymeric fibres, the widely used concepts of uniform stress and strain are examined for the analysis of fibre deformation. The use of advanced techniques such as Raman and infrared spectroscopies to follow molecular deformation in both rigid-rod (e.g. PpPTA, PBO, PBT, polyethylene) and natural (e.g. cellulose, collagen, silk, chitin) polymer fibres is presented. A clear distinction between fibres that have structures that are subjected to uniform stress or strain is presented, with the evidence that is detected from the response of the molecules (by Raman spectroscopy) and the crystalline fraction (by X-ray diffraction). It is suggested that natural fibres, such as cellulose, silk and others, may have different types of microstructures that are subjected to a uniform strain, which could have potentially led to incorrect determinations of crystal moduli. It is also demonstrated that the Raman and X-ray techniques have been influential on our development of fibres, and have shown that the morphology plays a critical role in mechanical properties. In addition to this, the use of X-ray diffraction using microfocus synchrotron sources is also reviewed. This approach allows a more complete picture of both molecular and crystalline deformations to be developed, and with the advent of nanocomposites it is shown that a combination of the two techniques will be vital for our understanding of their exploitation in technological applications.

Keywords

Fibres
Nanocomposites
Deformation

Cited by (0)

Professor Robert J. Young FREng, Head of the School of Materials – University of Manchester, UK. Professor Young was born in 1948. He studied Natural Sciences at the University of Cambridge, and gained a B.A. in 1969 and a Ph.D. (1973), after which he obtained a Research Fellowship at St. John's College, Cambridge. In 1975 he took up a Lectureship in Materials Science at Queen Mary College, London. He became Professor of Polymer Science and Technology in Manchester in 1986, a position which he still holds. During the same year he served as Head of the Department of Polymer Science and Technology, before taking up the role of Head of Manchester Materials Science Centre in 1987. From 1992 to 1997 he was the Royal Society Wolfson Research Professor of Material Science. Professor Young also chaired the Metallurgy and Materials panels for the UK Research Assessment Exercises in 1996 and 2001. In 2004 he was appointed Head of the School of Materials in the newly formed University of Manchester.

Professor Young's main research interest is the relationships between structure and properties in polymers and composites, publishing over 250 papers and a number of books. His research has been supported by the EPSRC, industry and the European Union and his interests have extended recently to the field nanotechnology. He has lectured extensively on the public understanding of science at the Royal Society (Zeneca Lecture), the British Association (Royal Society Lecture) and for a number of other organisations. He was elected as a Fellow of the Royal Academy of Engineering in 2006.

Dr. Stephen J. Eichhorn, Senior Lecturer in Polymer Physics and Biomaterials – University of Manchester, UK. Dr. Eichhorn was born in 1972 and studied his first degree in Physics at Leeds (B.Sc., 1993), a Masters at Bangor/University of Manchester (1995) and a Ph.D. at the University of Manchester (1999). He was appointed as a lecturer in Materials Science in 2002 and was promoted to Senior Lecturer in 2006.

Dr. Eichhorn's main research interest is the relationships between structure and properties in polymers and composites, with particular emphasis on natural materials. He has focussed mainly on cellulosic fibres and composites, with particular interests in using Raman spectroscopy to map local deformation. His research has been supported by the EPSRC, Nuffield Foundation and the Royal Society. He is a member of the American Chemical Society and is the membership secretary for the Cellulose and Renewable Materials division. Dr. Eichhorn has given numerous talks at international conferences, including ACS National Meetings and a Gordon research conference on “The Chemistry of Polysaccharides”. He has also, since joining the School of Materials, given talks to schoolchildren as part of a widening participation and liaison programme. Dr. Eichhorn is also a member of the Institute of Physics.