In situ 1H NMR studies of free radical cryopolymerization

Free radical polymerization of DMAAm (dimethylacrylamide)-co-PEG diacrylate in a semi-frozen aqueous solution was studied using 1H NMR, which enables to monitor the non-frozen water as well as the reaction of monomers over time. It was possible to confirm the presence of a heterogeneous system with a liquid phase where the monomers were concentrated and the reaction proceeded. The resulting macroporous polymeric structure with dense pore walls was confirmed using scanning electron microscopy (SEM).