Spectromechanical analysis of the structure and oxidation of PMR thermosetthermally-stable resins

The long-term ageing of high temperature polyimide thermoset polymers such as the commercial PMR15 resin and model molecules which compose the PMR15 c hemical structure, was studied. The amount of each oligomer directly influe nces the physicochemical and mechanical properties. The aim was to understa nd the oxidation mechanisms of these thermoset polyimide resins and the con sequences for the mechanical properties. Nuclear magnetic resonance analysi s has been associated with the thermomechanical transitions. (C) 2001 Elsev ier Science Ltd. All rights reserved.