Facile synthesis of novel HTPBs and EHTPBs with high cis-1,4 content and extremely low glass transition temperature

Abstract

Hydroxyl-terminated polybutadiene (HTPB) and epoxidized HTPB (EHTPB) with high cis-1,4 content, controllable molecular weight and relatively low PDI have been prepared via the selective oxidolysis process using commercial butadiene rubber (BR9000) as a starting material, including the one-pot synthesis of aldehyde group-terminated polybutadiene (ATPB) and the subsequent reduction reaction by sodium borohydride. The full process could be conducted in mild conditions and without complicated manipulations. By tuning the epoxy percent and chain-cleavage percent in the first step, liquid telechelic HTPBs with full-scale molecular weight and EHTPBs with various epoxy percent were readily obtained. The microstructure, molecular weight and PDI of products in each step were determined by FT-IR, 1H NMR, 13C NMR and GPC, respectively. The thermal properties of HTPBs and EHTPBs were tested by DSC and TGA.