Viscoelastic properties of polyurethane-poly(methyl-methacrylate) interpenetrating polymer networks

Abstract

The tensile and shear moduli of polyurethane-poly(methyl methacrylate( interpenetrating polymer networks (IPN’s) were evaluated. The tensile modulus was obtained on an Instron tensile tester and the shear modulus was measured on a torsion pendulum as a function of temperature and composition. In general, the modulus behavior followed the theoretical models of Budiansky, which predict a phase inversion. The mechanical damping was increased in the IPN’s but this increase was not characteristic of interpenetration since it was also found to occur in pseudo-IPN’s (only one network cross-linked) and in the linear blends.