Polystyrene-graft-poly(2,2 '-bithiophene): synthesis, characterization, and properties

Abstract

This paper describes a new approach for graft copolymerization of 2,2'-bithiophene onto a polystyrene (PSt) backbone by a multi-step process. For this purpose, first poly(styrene-co-4-chloromethyl styrene) [P(St-co-CMSt)] was synthesized via a free radical polymerization, and then the chlorine groups of P(St-co-CMSt) copolymer were converted to thiophene groups by a substitution nucleophilic reaction in the presence of a solvent composed of 2-hydroxymethylthiophene, sodium hydride, and dry tetrahydrofuran. The thiophene-functionalized polystyrene multicenter macromonomer obtained was used in oxidative copolymerization with 2,2'-bithiophene to yield a graft copolymer [polystyrene-graft-poly(2,2'-bithiophene) (PSt-g-PBT)]. The chemical structures of all samples as representatives were characterized by H-1 nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The thermal behaviors of the synthesized polymers were investigated by means of thermogravimetric analysis. Moreover, the conductivity of the PSt-g-PBT copolymer was measured by four-point probe method, and its electroactivity behavior was verified under cyclic voltammetric conditions.