Reversible addition-fragmentation chain transfer polymerization of 2-(dimethylamino)ethyl methacrylate/2-(dimethylamino)ethyl acrylate

Poly (2-(dimethylamino) ethyl methacrylate (PDMAEMA) and poly (2-(dimethylamino) ethyl acrylate (PDMAEA) were prepared by using chain transfer agents (CTA), dithioesters ( 2- ( ethoxycarbonyl) prop-2-yl dithiobenzoate(ECPDB), cumyl dithiobenzoate(CDB) and 1-phenylethyldithiobenzoate (PEDB) respectively, through reversible addition-fragmentation chain transfer (RAFT) polymerization. The molecular weight and molecular weight distribution of PDMAEMA and PDMAEA,were measured by gel permeation chromatography (GPC) and nuclear magnetic resonance spectrometer (H-1-NMR). The results showed the molecular weight distribution of PDMAEMA was narrow when the ECPDB/AIBN and CDB/AIBN as the initiator respectively. But the theoretical number average molecular weight M-n,M-th was not in good agreement with M-n,M-NMR and M-n,M-GPC. It demonstrated that the molecular weight of polymers could not be controlled. Its reason is probably that the balance of the reversible addition-fragmentation chain transfer is disturbed by unapt match of monomer and CTA. With changing monomer or CTA, the molecular weight of polymers can be controlled. Compared with the CDB/AIBN system, the molecular weight distribution of PDMAEA by using PEDB/AIBN was narrower, and the molecular weight was controllable.