Process for making thiophene and furfurane polymers

Claim 1

A process for preparing polymers of formula (I): ##STR5## wherein X is a sulphur or an oxygen atom: R 1 and R 4 are the same or different substituents selected from H, a C 1 -C 4 alkyl, a carbonitrile, a halide, a trihalomethyl and a phenyl group, and n has a value greater than 10, said process comprising (a) contacting a 2,5-bis-methylene halide substituted thiophene or furan with a sulphide of the formula R 2 R 3 S, wherein R 2 are R 3 are independently H or an alkyl group or together with the sulphur atom form a heterocyclic ring, to form a bis-sulphonium salt, (b) polymerising the bis-sulphonium salt of the bis-methylene halide substituted thiophene or furan in the liquid phase in the presence of an organic nitrogen containing base supported on a polymeric backbone capable of forming a quaternary ammonium halide which is insoluble in the liquid reaction phase to form a precursor polymer in solution, (c) separating a solution of the precursor polymer from the reaction mixture and recovering the precursor polymer from said solution, and (d) thermally decomposing the recovered precursor polymer to form the final polymer of formula (I).