H. Balcar et M. Pacovska, PURE WCL4-CATALYST FOR POLYMERIZATION OF NORBORNENE AND MONOSUBSTITUTED ACETYLENES, Journal of molecular catalysis. A, Chemical, 115(1), 1997, pp. 101-105
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.