POLYMERIZATION AND POLYMER PROPERTIES OF DIARYLACETYLENES

The polymerization of three diarylacetylenes, namely 1-(p-benzylphenyl )-2-phenylacetylene (p-BzDPA), 1-(p-phenylphenyl)-2-phenylacetylene an d 1-(beta-naphthyl)-2-phenylacetylene, was examined. These monomers po lymerized in good yields with TaCl5-cocatalyst systems. Poly(p-BzDPA) was soluble in various organic solvents and had high molecular weights of 6 x 10(5)-9 x 10(5) according to gel permeation chromatography. In contrast, the other two polymers were insoluble in all solvents. All these polymers had fairly good thermal stability in air (their onset t emperatures of weight loss in air were 330-450-degrees-C). The oxygen permeability coefficient of poly(p-BzDPA) at 25-degrees-C was 18 barre rs, which was close to that of natural rubber (23 barrers).