The present invention is directed to a free radical control agent of the structural formula: wherein R.sup.1 is a divalent alkyl group of 1 to 12 carbon atoms, R.sup.2 and R.sup.3 are each independently hydrogen or an alkyl group of 1 to 12 carbon atoms, and R.sup.4 is --OH or --COOH, with the proviso that the total carbon atoms of R.sup.1, R.sup.2, and R.sup.3 is no greater than 12; and wherein Y represents a functional group that is capable of activating a vinylic carbon toward free radical addition.