Energy Storage as the Characteristic Feature of Inelastic Deformation of Solid Polymers

Abstract

Deformation behaviour of solids must be characterised not only by conventional mechanical parameters, but also by thermodynamic quantities such as work (W), expended for deformation, heat of deformation (Q), and sample internal energy changes (AU). Absolute values and variations of these parameters are connected with the structural alterations in a solid under stress and with physical processes relating to deformation mechanisms operating in them. The aforementioned thermodynamic quantities are well documented for crystalline metals [Bever et al (1973)], rubbers [Godovsky (1993)] and glasses [Oleinik et al (1993), Godovsky (1993)]. However, such data is limited for polymeric crystals, semi-crystalline and LC polymers. The main objective of this paper is to review data of W, Q and ΑU for polymer solids of different structural organization, such as the glassy, LC, crystalline, semi-crystalline and blends. We will than compare the values and their changes with strain for different polymers in order to analyse them in a framework of deformation mechanisms operating in polymers of different structures.