Synthesis and Properties of Substituted Poly(phenylacetylene)s Having Biphenyl Moieties

Abstract

Novel phenylacetylene derivatives containing a biphenyl group were synthesized, and polymerized with Rh complex catalyst, [Rh(norbornadiene) Cl]₂. All polymers were soluble in organic solvents such as benzene, chloroform and THF. Their relative weight-average molecular weights determined by GPC were in the range of 40,000～60,000. These polymers were fairly thermally stable, judging from their high onset temperature (350～360 °C) of weight loss in TGA under nitrogen. The polymers obtained showed thermotropic nematic phases as observed by polarizing optical microscopy and DSC measurements.