Decoupling the Effects of the Matrix Properties and Foam Structure on the Mechanical Properties of Microcellular Foam by Sub-Tg Annealing

Abstract

Sub-T, annealing microcellular polycarbonate for 100 hours at 135°C increases yield strength but decreases fatigue life and ductility. Annealing reverses the effect of CO₂ saturation-cycling on the mechanical properties of the foam matrix by decreasing the free volume created by the saturation-cycle. Consequently, annealing decouples the effects of the matrix properties and the microstructure on the mechanical behavior of microcellular foam.