Considerable research efforts in recent years have been directed toward the synthesis, characterization and fabrication of benzobisazole rigid-rod polymers. These systems have exhibited excellent high strength, high-modulus values with superior thermal and thermaloxidative properties as compared to the state-of-the-art. Modulus values of 50-60 msi, with tensile strength of 500 ksi have been obtained on fibers after heat treatment. Although these fibers exhibit excellent mechanical properties, they suffer from relatively low axial compressive strength (50 ksi). Previous research has shown that labile pendant methyl groups attached to the polymer backbone offered a mechanism by which rigid-rod benzobisazole polymers could be crosslinked. Crosslinking of these fiber systems would offer a better comparison to carbon fibers which perform very good in compresion. The crosslink density could be manipulated by the synthesis of random copolymer compositions. This paper describes the work on the synthesis, fabrication and mechanical evaluation of a series of random copolymers having labile methyl groups for crosslinking.
|Number of pages||5|
|Journal||Polymeric Materials Science and Engineering, Proceedings of the ACS Division of Polymeric Materials Science and Engineering|
|State||Published - 1 Dec 1989|