Abstract
This paper is concerned with several fundamental aspects of the glassy polymer structure and properties. One aspect is chemical vitrification, the process whereby the reactants are transformed from the liquid into the glassy state due to chemical reactions. The influence of that transformation on the Young moduli and Tg of formed polymers is considered. This is exemplified by the epoxy cure process. Another aspect is the mechanism of plastic deformation of polymeric glasses and the third one is the isothermal enthalpy and volume relaxations in glassy polymers during physical aging. Choice of these topics is connected with their importance for polymer materials and advanced composite science. Some new experimental results for glassy polymers are introduced. The plastic deformation of glassy polymers is interpreted in the terms of two independent deformation modes. Mode I (low deformation temperature mode) is crystal-like and based on the nucleation and growth under stress of defects which have many features of dislocations. The second (high deformation temperature) Mode II is the diffusion motion of vacancies (holes) due to simultaneous action of stress and temperature. In the simultaneous measurement of volume and enthalpy isothermal relaxation a new type of relaxation asymmetry for sample contraction and expansion was found.
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