PURE WCL4-CATALYST FOR POLYMERIZATION OF NORBORNENE AND MONOSUBSTITUTED ACETYLENES

A suspension of commercial WCl4 initiates rapid polymerization of norb ornene and norbornadiene under mild conditions. If norbornenyl acetate is used as a substrate, WCl4 is dissolved and homogeneous polymerizat ion occurs. In both a cases polymers (<(M)over bar (w)> = about 80 000 ), the structure of which corresponds to the ring-opening metathesis m ode of polymerization, were prepared. WCl4 has also been found to poly merize monosubstituted acetylenes (benzene, 50 degrees C). Poly(t-buty lacetylene) of <(M)over bar (w)> = 600 000, poly(phenylacetylene) of < (M)over bar (w)> = 200 000 and poly(1-hexyne) of <(M)over bar (w)> = 1 4 000 were prepared in high yields. When WCl4 was dissolved in the rea ction with oxygen-containing compounds (e.g. methyl acetate, acetylace tone, acetophenone) before substrate addition, catalyst activity incre ased significantly. WCl4 in 1,4-dioxane was found to be a very active system for phenylacetylene polymerization; it polymerizes this monomer at the monomer-to-catalyst mole ratio equal to 1000 providing polymer of <(M)over bar (w)> = 400 000.