In situ Generated Dimethyl Dioxirane (DMD)/Copper(II) (2,2'-diamino-4, 4'-bithiazole) Complex as a New Oxidant for Polybutadiene and Hydroxyl Terminated Polybutadiene (HTPB) Epoxidation

Abstract

Epoxidation of polybutadiene and HTPB are performed by using in situ generated dimethyl dioxirane (DMD) as oxidant and copper(II) (2,2'diamino-4,4 '-bithiazole) (DABTZ) complex as the catalyst at 25°C. For comparison of double bond reactivities, epoxidation reactions are performed on three different types of polybutadiene and HTPBs containing various cis, trans, vinyl microstructures. The tendency of different C=C geometries towards epoxidation are evaluated in detail at various reaction times as well as catalyst concentration and the products are characterized by using 1H NMR, 13C NMR, and FT-IR spectroscopies. Spectra analysis did not show the formation of over-oxidation products even at long reaction times. Another important observation is the preservation of hydroxyl end groups in HTPB chain.