Investigation of temperature sensitivity behaviors of water soluble polyacrylamides

Temperature sensitive polymers with a lower critical solution temperature (LCST) are used in a variety of industries such as the pharmaceutical, cosmetic, food, and paint. These polymers are generally of the poly(N-alkylacrylamide) type, of which poly(N-isopropylacrylamide) (PNIPA) is the most commonly used. More novel poly(N-alkylacrylamide)s have also been the subject of much attention recently. In this study, N-alkylacrylamides containing different alkyl groups were synthesized by nucleophylic substitution reactions of various amines with acryloyl chloride. They were polymerized using the solution polymerization method, and the temperature sensitivities of the polymers were investigated. For this purpose, three monomers, N,N-diethylacrylamide, N-cyclopropylacrylamide, and 4-piperidineethanolacrylamide, were synthesized using diethylamine, cyclopropylamine, and 4-piperidineethanol, as the amines, respectively. The obtained polymers, poly(N,N-diethylacrylamide) (PDEA), poly(N-cyclopropylacrylamide) (PCPA), and poly(4-piperidineethanolacrylamide) (PPEA), were found to be thermoresponsive, particularly PPEA is a potential novel material that can be utilized as an alternative to the common temperature sensitive polymers. The effects of several conditions on the LCST and the critical flocculation temperature (CFT) of the polymers were also investigated. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013