Studies on the polymerization of bifunctional monomers. XXI. Polymerization of o‐diethinylbenzene

Abstract

AbstractPolymerizations of o‐diethinylbenzene were conducted with ZIEGLER‐type and other catalysts. Polymers were readily obtained with equation image as catalysts. Combinations of alkylaluminium compounds with other transition metal acetylacetonates were much less effective as catalysts. The polymers obtained with these catalysts are pale brown to brown powders with a mol. wt. of 2000 to 3500, which do not melt nor decompose up to 300°C. Small amounts of polymers were also obtained with cationic catalysts and with azobisisobutyronitrile as initiator.From NMR and IR spectroscopic data, the polymers obtained with coordination catalysts were shown to contain 30–50% of the unreacted second ethinyl group. The methyleneindene unit probably is involved as cyclic structure, although other structural units formed by head‐to‐head addition could not be excluded from the data available.