Bismaleimide/preceramic polymer blends for hybrid material transition regions

Abstract

In this article, initial steps were taken in the study of processing mixtures of a polymer and a preceramic polymer to produce a hybrid material that contains a region of gradual transformation from a polymer to a ceramic. It is thought to be a first step toward the eventual development of a hybrid that is graded from a polymer matrix composite to a ceramic matrix composite. Thermal analysis, elemental analysis, and morphology characterization of blends of RD-730 preceramic polymer, which converts to silicon carbide upon pyrolyzation, and Matrimid A/B polymer which is a bismaleimide were carried out as a function of cure cycles. The cure cycles were chosen to vary the resin viscosity at specific times during processing in order to affect the amount of phase separation of the two resins. These results were then used to make conclusions on how processing parameters affected the miscibility of the two resins and the likelihood of producing a hybrid having mechanical and thermal properties that fall between those of the two constituents. High RD-730 loadings were achieved without phase inversion, the glass transition temperature ( Tg) of the blended material was shown to be significantly influenced by a post-cure, and a spatial gradient in RD-730 concentration was noted.