Effect of chemical copolymerization and mixed chain extenders on mechanical properties of HTPB polyurethane

Abstract

In this study, three kinds of polyurethane materials based on HTPB were prepared by copolymerization of hydroxyl-terminated polybutadiene (HTPB) and hydroxyl-terminated polyethylene glycol-tetrahydrofuran copolyether (HTPE) and adding mixed chain extender, polyether polyols HEP-330N and 2-hydroxyethyl disulfide (HEDS). The effects of copolymerization and mixed chain extender on the mechanical properties of polyurethane were studied by static tensile test, dynamic mechanical property analysis (DMA) and differential scanning calorimetry (DSC). Among them, compared with pure HTPB, the tensile strength and elongation at break of polyurethanes obtained by copolymerization, the polyurethanes obtained by adding mixed chain extender, and the polyurethanes obtained by both of these two methods were significantly improved, and the storage modulus and loss modulus were also improved. In addition, the glass transition temperature of polyurethane remained basically unchanged, which was in the range of -79°C to -75°C. It was much lower than the room temperature, which would make it more widely used. This effective method will provide an opportunity for the synthesis of various high-performance composites.