Polybenzimidazole (PBI) and polyarylate blends

Abstract

The discovery of new polymeric alloys by blending commercially available polymers is an exciting trend in materials development. The ability to tailor existing materials to a new /unique set of property /performance /price specifications through combinations of materials is the key reason for this growth. Recently, various miscible blends based on Hoechst Celanese's polybenzimidazole ( PBI ) and commercially available polyimides (PI) were di~covered.'-~ Blend miscibility was evidenced in the form of changes in IR spectra, single Tg's, and well-defined single tan 6 relaxations. The intermolecular interaction involving the =NH and carbonyl groups was the major driving force for the miscibility. We therefore conducted a program focused on the fabrication of high-performance blend fibers based on PBI. After a thorough investigation, we found that PBI not only has superior thermal / chemical properties, but also exhibits unique reactivity that enables it to interact with other functionalized polar molecules and to possibly form compatible binary system^.^^^ As a result of PBIs reactivity, the molecular interactions between PBI and polyarylate ( PA) polymers have recently been discovered at Hoechst Celanese Research Division? In this paper we present information regarding the assessment of PBI/PA compatibility, the preparation /characterizations of solution and blend film, as well as the development of PBI/PA fibers.