Thermal characterization of PMR polyimides

Polyimides are attractive for high temperature applications as the matrix r esins, due to their excellent thermo-oxidative stability and mechanical pro perties. As composite materials for aerospace applications, they possess ce rtain unique characteristics such as toughness, resistance to temperature a nd solvents as well as high tensile strength and modulus. A series of novel PMR polyimides based on substituted benzidines are examined and compared t o the state-of-the-art PMR-15. The assigned glass transition temperatures a nd the mechanism for the thermal decomposition of four specific PMR polyimi des are obtained, using thermal mechanical analysis and TGA/FTIR/MS techniq ues, Their thermal decomposition steps are proposed, identified and also co mpared to each other. (C) 2001 Elsevier Science B.V. All rights reserved.