Grafting of n-butyl acrylate and N,N '-dimethyl acrylamide from poly(divinylbenzene) microspheres by RAFT polymerization

N,N'-Dimethyl acrylamide and n-butyl acrylate have been grafted from crosslinked poly( divinylbenzene) core microspheres by both reversible addition-fragmentation chain transfer (RAFT) polymerization and conventional free radical polymerization. The microspheres were prepared by precipitation polymerization utilizing 55 and 80 wt. % divinylbenzene (DVB), respectively. The RAFT agent cumyl dithiobenzoate (CDB) was utilized and grafting was performed in toluene at 80 degrees C with 2,2'-azoisobutyronitrile (AIBN) as thermal initiator. Particle weights increased up to 6% for poly(n-butyl acrylate) and up to 15% for poly(N,N'-dimethyl acrylamide). Grafting from poly(DVB-55) microspheres results in a higher particle weight increase than grafting from poly(DVB-80) microspheres while using the same RAFT agent concentrations. The particle weight increase is approximately higher by a factor of two. The grafted microspheres were characterized by attenuated total reflection (ATR) IR spectroscopy and scanning electron microscopy.