DIACETYLENE-CONTAINING POLYMERS .8. SYNTHESIS AND CHARACTERIZATION OFNOVEL HIGH-MOLECULAR-WEIGHT DIACETYLENE-CONTAINING POLY(ESTER-CO-URETHANES)

Novel high molecular weight diacetylene (DA) - containing polymers, po ly{[bis(3-butynyl) 3,5-diynylene sebacate]-co-[bis(3-butynyl) hexameth ylenedicarbamate]}s, were synthesized and characterized. The copolymer s were found to be semicrystalline and their degree of crystallinity w ent through a minimum due to a random composition of the copolymers. T he copolymers containing less than 40 mol-% of bis(3-butynyl) hexameth ylenedicarbamate (2) were found to be thermoplastic. The glass transit ion temperature of the copolymers tends to increase with increasing mo nomer 2 content. All the copolymers underwent topochemical cross-polym erization on electron-beam irradiation or heating in the solid state a nd the maximum of the visible absorption spectra of the cross-polymeri zed copolymers showed a long wavelength shift with increasing monomer 2 content. Upon introduction of 10 mol-% of the urethane monomer 2 the tensile strength of the copolymer increases from 250 MPa to 280 MPa.