End-groups in poly(methyl methacrylate) and polystyrene prepared by radical polymerization in the presence of derivatives of stilbene

Polymers of methyl methacrylate and styrene have been prepared in the presence of low concentrations of various para-derivatives of stilbene, using ¹³C-benzoyl peroxide as the source of the initiating radicals. Examination of the ¹³C-NMR signals due to benzoate end-groups showed that in each case a high proportion of the initiator fragments was attached to a stilbene unit. The results indicate that each of the stilbenes has very high reactivity towards the benzoyloxy radical, depending upon the nature of the substituent. Radical polymerization involving benzoyl peroxide and a stilbene provides a method for the preparation of polymers with special end-groups.