The mechanisms by which a new nonionic alkenyl-based surfmer (Maxemul 5011(TM)) was involved in acrylic emulsion polymerization were investigated. No proof of homopolymerization or of chain transfer to surfmer was obtained under the conditions studied. The effect of the initiator type, feeding time of the surfmer, particle size of the seed, and surfmer concentration, on kinetics and surfmer incorporation showed that the surfmer reacted mainly by copolymerization with the monomers in the outer shell of the polymer particles. (C) 2004 Wiley Periodicals, Inc.