Metathesis copolymerixation of norbomene (NBE) with tert-butylacetylene (t-BA) at a feed ratio of 1: 1 initiated by a tungsten carbene complex was investigated under various conditions. Results obtained from time-conversion curves indicated that the reactivity of tert-butylacetylene was several times greater than that of norbomene. The copolymer was obtained in a higher yield and a larger molar mass in the solvent CCL than those of other chlorinated hydrocarbons such as CHCl, and CH,Cl,. A larger molar mass and higher yield of copolymer were also obtained in the presence of a Lewis acid such as AlCl,.
The activity of the tungsten carbene complex was obviously affected by Lewis acidity. '%2 NMR analysis results revealed a content of t-BA unit of the copolymer in the presence of a Lewis acid. When copolymerization of norbomene (M,) with tert-butylacetylene (M2) in toluene was studied at 3o"C, the monomer reactivity ratios were calculated to be r, = 0.42 (kO.02) and r2 = 2.20 (+ 0.05) with the method used by Mayo and Lewis. When in chlorinated solvents the copolymer was irradiated with ultraviolet light, the copolymer degraded and the rate of degradation was found to be the greatest in highly chlorinated solvents such as Ccl,. Thermogravimetric analysis results of the copolymer indicated that there was no significant loss of mass that occurred below 250Β°C under nitrogen.