Solid-Phase Thermal Polymerization of Macrocyclic S-Aryl Thioester Trimer with 5-t-Butylisophtaloyl Skeleton Using Crown Ether Complexes

Abstract

Thermal polymerizations of macrocyclic S-aryl thioester trimer with a 5-t-butylisophtaloyl skeleton (m-CTE-3) were investigated. The polymerization of m-CTE-3 without catalysts occurred at over 260°C in the solid state and heating at 280°C for 10 min produced a polymer with a M _w of 370 000. Quaternary onium salts or crown ether complexes enhanced the solid-phase thermal polymerization of m-CTE-3. In the case of the polymerization using 18-crown-6 ether (18-C-6)/potassium halide complexes, the polymerization occurred at around 200°C. It was proved that 18-C-6/KBr was the most effective catalyst to produce high molecular weight polymers with M _w as much as 850 000. It was also suggested that the solid-phase polymerization proceeded in a chain-growth reaction mode.