ETHYNYL-TERMINATED POLYETHERS FROM NEW END-CAPPING AGENTS .2. END-CHAIN FUNCTIONALIZATION THROUGH NITRO DISPLACEMENT

Ethynyl-terminated polysulfones and ethynyl-terminated polyether-ketones were prepared in a one-step polyetherification reaction using new end-capping agents, respectively 4-ethynyl-3'-nitrodiphenylsulfone and 4-ethynyl-4'-nitrobenzophenone. These reagents were prepared according to a three-step route each. End-capping of the polymers involve the nitro displacement by a phenoxide ion. The nitro group was found to be more reactive than the fluoro one as a leaving group. Due to the thermally induced reaction of their ethynyl end-groups, the polymers lead to materials with improved glass transition temperatures and good thermostability.