THERMOSENSITIVE HYDROGELS FROM COPOLYMERS OF N-ISOPROPYLACRYLAMIDE AND ANIONIC MONOMERS

Thermosensitive hydrogels containing anionic monomer have been prepare d from copolymerization of N-isopropylacrylamide and 3-sulphopropylacr ylate potassium salt, 3-sulphopropylmethacrylate potassium salt and 2- acrylamido-2-methyl-1-propanesulphonic acid in the presence of N,N'-me thylene-bisacrylamide as crosslinking agent with potassium persulphate /N,N,N',N',-tetramethylethylenediamine as initiator in water at room t emperature. The swelling behaviour and volume transition temperature o f the gels containing different anionic monomers were studied. It was found that with increasing content of anionic monomer, the swelling ra tio as well as the volume transition temperature of the gel increased. The swelling behaviour of the gels in salt-containing water was inves tigated.