Sulfone/ester polymers containing pendent ethynyl groups

Sulfone/ester polymers containing pendent ethynyl groups were prepared by multistep and direct routes. Hydroxy-terminated sulfone oligomers(M _n = 2650 and 8890 g/mol) were reacted with diacid chlorides to yield high-molecular-weight polymers. In the multistep route, a pendent bromo group on the polymer was converted to an ethynyl group. In the direct route, the hydroxy-terminated sulfone oligomers were reacted with a stoichiometric amount of 5-(4-ethynylphenoxy)isophthaloyl chloride to yield high polymers. The pendent ethynyl groups on the sulfone/ester polymers were reacted in the 200 to 300°C range to provide branching and crosslinking. The resultant polymers exhibited higher T_gs and better resistance to chloroform than comparable polymers void of ethynyl groups. Films of the cured polymers displayed good mechanical properties. The synthesis and characterization of the monomer, oligomers, and polymers are discussed.