2-Styrylfuran (STF) resembles stilbene and certain other 1,2-substituted ethylenes, e.g. 2-styrylthiophene, in being very effective in capturing benzoyloxy radicals. When STF is used as an additive during polymerization of a monomer such as methyl methacrylate with benzoyl peroxide as initiator, it is incorporated preferentially at sites adjacent to benzoate end-groups to give macromolecules with furyl groups very close to chain-ends.