Radical alternating copolymerization: A strategy for hyperbranched materials

Novel hyperbranched polymers were synthesized in a high yield without gelat ion through the free-radical alternating copolymerization of an AB/B' (ally loxy maleic acid/maleic anhydride) system, in which group B and monomer B' both could only alternately polymerize with group A. The arm number of the produced highly branched polymers was equal to the product of the linear ch ain length and the probability of pendent B groups being growing centers. T he molecular weight of these novel hyperbranched polymers increased with in creasing initiator concentration and prolonged polymerization times. The AB /B' system, used as described, provides a new general methodology for highl y branched and functional polymers. (C) 2000 John Wiley & Sons, Inc.