T. Masuda et H. Tachimori, DESIGN, SYNTHESIS, AND PROPERTIES OF SUBSTITUTED POLYACETYLENES, Journal of macromolecular science. Pure and applied chemistry, A31(11), 1994, pp. 1675-1690
This article reviews recent topics on the polymerization of substitute
d acetylenes, focusing on the synthesis of poly(diphenylacetylenes) an
d the living polymerization of phenylacetylenes. Diphenylacetylene (DP
A) polymerizes with TaCl5-n-Bu(4)Sn to give a polymer which is thermal
ly very stable but insoluble in any solvents. DPAs with various groups
(e.g., p-Me(3)Si, m-Me(3)Ge, p-t-Bu, and p-PhO) polymerize similarly.
These polymers are soluble and their ($) over bar M(w)'s reach 1 x 10
(6) to 3 x 10(6). Some of them are more gas-permeable than poly(dimeth
ylsiloxane). Several acetylenes (e.g., ClC = C-n-C6H13 and HC = C-t-Bu
) have been found to undergo living polymerization with MoOCl4-n-Bu(4)
Sn-EtOH. Whereas phenylacetylene (PA) does not polymerize in a living
fashion, ortho-substituents in PA more or less suppress termination an
d chain transfer. PAs with bulky ortho groups (e.g., CF3 and Me(3)Ge)
especially undergo virtually ideal living polymerization.