Polybutadiene and hydroxyl-terminated polybutadiene epoxidation using in situ-generated Dimethyl Dioxirane (DMD)/transition metal salts complex

Abstract

Epoxidation of polybutadiene (PB) and hydroxyl terminated polybutadiene (HTPB) was performed using in situ-generated dimethyl dioxirane (DMD) as an oxidant and some transition metal salts as catalysts. Differences in the degree of epoxidation of various C=C bonds was evaluated in detail at various reaction times. That is, cis C=C bonds had a relatively high reactivity which is known to be easily epoxidized. Remarkable selectivity of DMD for epoxidation of HTPB double bonds toward OH end groups was observed. Among salts, CuSO4 ̇ 5H2O showed the highest yields in combination with DMD and reaction factors such as reaction time as well as different concentrations of this salt are examined in detail. This procedure is easy, eco-friendly, convenient and the reaction conditions are straight forward. © 2008 Koninklijke Brill NV.