Melt grafting of t-butylaminoethyl methacrylate onto polyethylene

Abstract

The preparation of a polymer containing secondary amino groups by grafting of t-butylaminoethyl methacrylate (t-BAEMA) onto linear low-density polyethylene (LLDPE) in the melt has been investigated. Using a peroxide initiator, the effects of feed composition and reaction time were studied. Materials containing up to 3 wt% grafted t-BAEMA, 5 wt% t-BAEMA homopolymer and displaying minor crosslinking were obtained by the choice of appropriate feed composition and reaction conditions. Attempts were made to increase the degree of grafting and to minimize the homopolymerization by adding a variety of compounds. The homopolymerization was considerably reduced and relatively high grafting efficiency achieved by using p-benzoquinone as a chain terminator. Carbon tetrabromide, a chain transfer agent, suppressed polyethylene crosslinking but decreased grafting and increased homopolymerization. n-Hexane, known to be able to accelerate radiation-induced solution grafting of t-BAEMA onto a PE film, only accelerated t-BAEMA homopolymerization rather than grafting for this peroxide-initiated melt grafting case. Other compounds containing nitrogen, phosphorous or sulphur, known to be chain terminators for maleic anhydride and methyl methacrylate homopolymerization, acted only as inert additives. Preliminary studies on the potential interpolymer melt reaction between this graft polymer and acid polymers are also reported.