GRAFTING AND DEGRADATION REACTIONS AT THE SYNTHESIS OF INTERPENETRATING POLYMER NETWORKS IN-SITU FROM POLYETHYLENE AND BUTYL METHACRYLATE

The grafting and degradation reactions accompanying the synthesis of i nterpenetrating polymer networks (IPN) in situ consisting of polyethyl ene (PE) and poly(butyl methacrylate) (PBMA) were investigated under m odel conditions. After polymerization at 110 degrees C it was found th at the 2,5-dimethyl-2,5-di-(t-butylperoxy)hexan (Luperox-101) had a de structive effect on the PBMA network formed provided the temperature w as raised to 160 degrees C. Simultaneously in this reaction stage, fur ther linkage of the PBMA chains with PE originates from a recombinatio n of macroradicals from both polymers. In the thermally initiated poly merization 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 o f PE grafting with BMA was observed. A considerable degree of PE cross linking and grafting of PBMA onto a PE network was achieved if both po lymers were mixed with 3 mass % of Luperox-101.