Diacetylene-containing polymers, 8. Synthesis and characterization of novel high molecular weight diacetylene-containing poly(ester-co-urethanes)†

Novel high molecular weight diacetylene (DA) - containing polymers, poly([bis(3-butynyl) 3,5-diynylene sebacate]-co-[bis(3-butynyl) hexamethylenedicarbamate] is, were synthesized and characterized. The copolymers were found to be semicrystalline and their degree of crystallinity went through a minimum due to a random composition of the copolymers. The copolymers containing less than 40 mol-% of bis(3-butynyl) hexamethylenedicarbamate (2) were found to be thermoplastic. The glass transition temperature of the copolymers tends to increase with increasing monomer 2 content. All the copolymers underwent topochemical cross-polymerization on electron-beam irradiation or heating in the solid state and the maximum of the visible absorption spectra of the cross-polymerized 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.