DIACETYLENE-CONTAINING POLYMERS .7. SYNTHESIS AND CHARACTERIZATION OF NEW DIACETYLENE-CONTAINING POLYESTERS AND COPOLYESTERS DERIVED FROM DIPROPARGYL-1,10-DECANATE, DIPROPARGYL TEREPHTHALATE, 4,4'-DIPROPARGYLOXY DIPHENYL, AND 4,4'-BIS[(5-CARBOPROPARGYLOXY)PENTOXY]DIPHENYL

A series of new thermoplastic diacetylene containing polyesters and copolyesters was synthesized and characterized. The copolyesters had melting points as low as 50-degrees-C and were topochemically cross-linkable on electron beam irradiation. One of the copolymers was found to form a nematic melt in the region of 48-67-degrees-C and was cross-polymerizable in the liquid-crystalline state to form a polydiacetylene network. The tensile strength and Young's moduli of the polymers reached as high as 145 MPa (1 Mrad) and 535 MPa (5 Mrad) respectively. The values decreased with decrease in degree of crystallinity or melting point of the crystallites and the tensile strength went through a maximum on irradiation with an electron beam. Electron beam irradiation brought about a decrease in elongation at the break and increase in Young's modulus.