Patent ID: 7361716

Claim:
A method of preparing a polymer which comprises structural units of formula I, in which formula: Ar is an aromatic cyclic system with 4 to 20 carbon atoms, which may be substituted with a substituent chosen from the group consisting of a non-branched C 1 -C 20 -alkyl, a C 3 -C 20 -alkoxy, a C 1 -C 20 -alkylsulfate, a branched C 3 -C 20 -alkyl, a phenyl group and a benzyl group and which may comprise up to 4 heteroatoms chosen from the group consisting of oxygen, sulfur and nitrogen in the aromatic cyclic system, t is equal to 0, 1 or 2, R 1 is chosen from the group consisting of a non-branched C 1 -C 20 -alkyl group, a branched C 3 -C 20 alkyl group, a cyclic C 4 -C 20 -alkyl group, a C 1 -C 4 -alkyl-substituted cyclic C 4 -C 20 -alkyl group, a phenyl group and a benzyl group, which groups may comprise heteroatoms, R 2 and R″ 2 are each chosen for the group consisting of a hydrogen atom, a C 1 -C 20 -alkyl group, and a C 4 -C 20 -aryl group, which groups may comprise substituents, characterized in that the method starts with a compound having the formula II in which formula R′ 1 is chosen from the group consisting of a non-branched C 1 -C 20 -alkyl group, a branched C 3 -C 20 -alkyl group, a cyclic alkyl group, a C 1 -C 4 -alkyl-substituted cyclic alkyl group, a phenyl group, and a benzyl group, which groups may comprise heteroatoms, R 1 , R 2 and Ar are equal to R 1 , R 2 and Ar in formula I, and R′ 2 is chosen from the group consisting of a hydrogen atom, a C 1 -C 20 -alkyl group, an a C 4 -C 20 -aryl group, which groups may comprise substituents, and that the polymer with structural units of the formula I is prepared through polymerization with the aid of a base into a polymer which comprises units having the formula III in which formula R 1 , R 2 and Ar are equal to R 1 , R 2 and Ar in formula II, and R″2 is chosen from the group comprising R 2 and R′ 2 , and for the preparation of the polymer with units having the formula I, in which formula t is equal to 1 or 2, through oxidation of at least a number of the units of the polymer having the formula III.