Effects of crosslink density on mechanical properties of high glass transition temperature polycyanurate networks

Abstract

Polycyanurate networks of different architecture were synthesized using different curing cycles. Networks with a variable extent of reaction were obtained; the small variation of the cyanate conversion (0.8 to 1) corresponds to a large variation of glass transition temperature (150–290°C) and crosslink density. The mechanical behavior at small and large deformations and the fracture toughness were examined at room temperature and related to the network structural parameters. To explain the puzzling variation of the yield stress and yield strain with the cyanate conversion, recovery experiments were conducted to discriminate anelastic deformation from plastic deformation. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2471–2479, 1997