Graft polymerization of vinyl monomers inside macroporous polyacrylamide gel, cryogel, in aqueous and aqueous-organic media initiated by diperiodatocuprate(III) complexes

Graft polymerization initiated by diperiodatocuprate(III) complex (Cu(III)) initiator was found to be an effective and convenient method for graft polymerization of vinyl monomers onto macroporous polyacrylamide gels, the so-called cryogels (pAAm-cryogels). The effect of time, temperature, monomer and initiator concentration during the graft polymerization in aqueous and aqueous-organic media was studied. The graft polymerization of water-soluble monomers as [2-(methacryloyloxy)ethyl]-trimethylammonium chloride, 2-hydroxyethyl methacrylate, N-isopropylacrylamide, and N,N-dimethylacrylamide proceeds with higher grafting yield in aqueous medium, as compared with that in aqueous-organic media. Graft polymerization in aqueous-organic media such as water-DMSO solutions allows grafting of water-insoluble monomers such as glycidyl methacrylate and N-tert-butylacrylamide with high grafting degrees of 100 and 410%, respectively. It was found that the deposition of initiator on the pore surface of cryogels promoted graft polymerization by facilitating the formation of the redox couple Cu(III)-acrylamide group.