Synthesis of Carboxy terminated Polybutadiene (CTPB) Resin Using Oxidative Clevage of Polybutadiene Rubber and Transformation of Terminal Functional Groups

Carboxyl-terminated polybutadiene (CTPB) is a widely used polymer as a resin for fabrication of elastomers, sealants, electric insulation, and as a modifier of epoxy resins. In this paper, carboxyl-terminated polybutadiene resin was synthesized via the oxidative chain cleavage of polybutadiene rubber followed by the oxidation of aldehyde end-groups. The cleavage of polybutadiene rubber was performed using periodic acid and the solid rubber was converted to a liquid resin due to the decrease in the molecular weight of the polymer. This reaction also leads to the formation of aldehyde groups at the end of the cleaved chains. Then, CTPB resin was synthesized by oxidation of terminal aldehyde groups to carboxyl groups using Jones reagent. The microstructure and other properties of the polymers were characterized by FTIR, 1H NMR, 13C NMR, and GPC. The results indicated that the molecular weight (Mn) and functionality (F) of the resulting CTPB are 1652 g/mol and 1.8, respectively. In this method, the product was successfully synthesized with preserved microstructure.