Grafting and Degradation Reactions at the Synthesis of Interpenetrating Polymer Networks in Situ from Polyethylene and Butyl Methacrylate

Abstract

The grafting and degradation reactions accompanying the synthesis of interpenetrating polymer networks (IPN) in situ consisting of polyethylene (PE) and poly(butyl methacrylate) (PBMA) were investigated under model conditions. After polymerization at 110°C it was found that the 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane (Luperox-101) had a destructive effect on the PBMA network formed provided the temperature was raised to 160°C. Simultaneously in this reaction stage, further linkage of the PBMA chains with PE originates from a recombination of macroradicals from both polymers. In the thermally initiated polymerization of BMA (in the absence of peroxide), PE is grafted with BMA but no crosslinking of PE takes place. If a mixture of initiators (2,2′ - azo-bis-isobutyronitrile and Luperox-101) was used, a retardation of PE grafting with BMA was observed. A considerable degree of PE crosslinking and grafting of PBMA onto a PE network was achieved if both polymers were mixed with 3 mass % of Luperox-101.