The effect of additives on the enhancement of methyl methacrylate grafting to cellulose in the presence of UV and ionising radiation

The role of various additives in the grafting of methyl methylacrylate (MMA) to cellulose using UV and ionising radiation has been investigated. MMA grafting yields are hampered by competing homopolymerisation. The styrene comonomer technique was utilised to overcome this problem. The role of acid in these reactions has been studied as well as additives like, an inclusion compound (urea), thermal initiators and photoinitiators. Methanol was used as the swelling agent in all the experiments. Molecular weight studies with homopolymers indicate that both chemical and physical processes are involved in the mechanism of the reaction. The physical process involves a partitioning phenomenon whereas the chemical process concerns additional radical reactions in the radiation initiation step. This grafting mechanism is shown to be applicable to the simple radiation polymerisation of monomers in solution and also analogous UV fast curing systems. (author)