Styrene and methyl methacrylate were copolymerized at 323 K in the presence of a polybutadiene seed latex in emulsifier-free semi-continuous and, for comparison, batch processes using cumene hydroperoxide as initiator. Graft polymer characteristics were studied including the intra- and intermolecular microstructure. In contrast to expectation, the free and graft copolymers resulting from the semi-continuous processes under starved conditions appeared to have even broader distributions than the copolymers formed in the batch processes.