Polymer, Vol.46, No.25, 11786-11797, 2005
Non-linear, rate-dependent strain-hardening behavior of polymer glasses
This study is concerned with the finite, large strain deformation behavior of polymeric glasses. True stress-strain curves in uniaxial compression obtained for five different polymeric glasses: polycarbonate, polystyrene, poly(2,6-dimethyl-1.4-phenylene oxide), and linear and cross-linked poly(methylmethacrylate), revealed a strain-hardening response during plastic deformation that is strain-rate dependent and deviates from neo-Hookean behavior. An empirical modification of the so-called compressible Leonov model by a strain dependent activation volume is suggested, which describes the strain-rate dependent large strain behavior of these glassy polymers in good agreement with experimental data. (c) 2005 Elsevier Ltd. All rights reserved.