Ethynyl‐terminated polyarylates: Synthesis and characterization

Hydroxy‐terminated polyarylates (HTPA) with number‐average molecular weights of approximately 2500, 5000, 7500, and 10,000 were synthesized and converted to corresponding 4‐ethynylbenzolyloxy‐terminated polyarylates (ETPA) by reaction with 4‐ethynylbenzoyl chloride. The terminal ethynyl groups were thermally reacted to provide chain extension and crosslinking. The cured ETPA exhibited higher glass transition temperatures ( T g ) and better solvent resistance than a high molecular weight linear polyarylate. Solvent resistance was further improved by curing 2,2‐bis(4‐ethynylbenzoyloxy‐4′‐phenyl) propane, a coreactant, with ETPA at concentrations of approximately 10% (w/w).