Cloisite 15Aº nanoclay as an effective PTC for the epoxidation of hydroxyl terminated polybutadiene (HTPB)

Mir Mohammad Alavi Nikje,Maryam Gholi Nataj

doi:10.1590/0104-1428.1622

Abstract

A simple method is reported for the epoxidation of hydroxyl-terminated polybutadiene (HTPB) by using in-situ generated dimethyl dioxirane (DMD) as an oxidant and Cloisite 15Aº nanoclay as a phase-transfer catalyst (PTC). In order to find the optimum reaction conditions, real time analyses of the products as well as epoxidation progress, followed by ¹HNMR and FTIR techniques at various reaction times and different PTC concentrations, were done. Obtained data revealed the selectivity of DMD/ Cloisite 15Aº in predominant cis double bonds epoxidation in comparison with trans and pendant vinyl functional groups.

Highlights

The hydroxyl-terminated polybutadiene (HTPB) is widely used peracids appear to be more effective than peroxides in epoxidation reactions, they have harmful effects on human as a binder in the formulation of adhesives, solid rocket health and gives rise to environmental pollution[12]
The HSO5− anion is formed from the dissolution of Oxone in water that cannot penetrate into the polymer contained organic phase
Cloisite 15Ao acts as the phase-transfer catalyst that has quaternary ammonium salt with two long unbranched aliphatic tails and has the ability to transfer HSO5− from aqueous phase to solvent phase

Summary

Introduction

M-Chloroperbenzoic acid (m-CPBA) has been used as the oxidant in epoxidation of internal C=C bonds and data published by Saffers research group[10] Akcelrud and his coworkers reported the direct and polybutadiene and HTPB epoxidation using in-situ generated DMD in the presence of tetra-n-butyl ammonium bromide as a phase transfer catalyst (PTC)[20,21], MoO3[22], transition metal salts[23], copper (II) complex[24], Nano TiO2[25] and Cloisite 30B as a PTC[26,27]. Based on our literature survey, the epoxidation of HTPB by using in-situ generated strait forward HTPB epoxidation reaction for the first time DMD and Cloisite 15Ao is reported for the first time and by complete structural elucidation of reaction products. can be included as a simple and convenient method in

Methods

Results

Conclusion