Synthesis and properties of polyacetylenes with adamantyl groups

Three disubstituted acetylenes with an adamantyl group-1-(p-adamantylphenyl )-2-chloroacetylene (ClpAdPA), 1-(p-adamantylphenyl)-1-propyne (pAdPP), and 1-(p-adamantylphenyl)-2-phenylacetylene (pAdDPA)-polymerized in good yield s in the presence of MoCl5- or TaCl5-based catalysts. The highest weight-av erage molecular weights of poly(ClpAdPA), poly(pAdPP), and poly(pAdDPA) rea ched 3.6 x 10(5), 1.1 x 10(6), and 6.0 x 106, respectively. The polymers we re yellow to white solids and completely soluble in toluene, chloroform, an d so forth. These polymers thermally were fairly stable, and the onset temp eratures of weight loss in air were over 360 degrees C. Poly(pAdPP) and pol y(pAdDPA) provided free-standing films by solution casting, and their oxyge n permeability coefficients (P-O2) at 25 degrees C were 8.6 and 55 barrers [1 barrer = 1 x 10(-10) cm(3).(STP).cm/(cm(2).s.cm Hg)], respectively, whic h are relatively small compared to those of other substituted polyacetylene s. (C) 1999 John Wiley & Sons, Inc.