Radiation-induced polymerization of styrene in amines

Radiation-induced polymerization of styrene in amines was carried out mainly under employment of n-butylamine in a wide range of dose rate at room temperature. The rate of polymerization was measured and GPC analysis of the products conducted. It was found that the products consisted essentially of four fractions, i.e., oligomer, radical polymer, cationic polymer and super polymer. Butylamine is a strong inhibitor for cationic polymerization. For example, 3 x 10-3 mole/l butylamine in styrene solution can inhibit the formation of cationic polymer to a greater extent. Radical polymerization is initiated by radicals formed not only from styrene but also from butylamine. The rate constant of initiating radical formation of butylamine was found to be five times greater than that of styrene independent of dose rate. The dependence of the total rate of polymerization of styrene on the styrene content at various dose rates may be explained with the higher rate of initiating radical formation of butylamine. Chain transfer of growing chains to butylamine was also investigated. However, the contribution of transfer was negligible compared to that of mutual termination of growing chains for the stable polymer formation. (author)