Journal of Applied Polymer Science, Vol.64, No.8, 1477-1484, 1997
Thermoreversible Hydrogels .1. Synthesis and Effect of a Hydrophobic Monomer on Swelling Behaviors of Thermoreversible Gels Prepared by Copolymerizing N-Alkoxyalkylacrylamide with Butyl Acrylate
A series of copolymeric gels were prepared from N-alkoxyalkylacrylamide and n-butyl acrylate (BA) at various feed ratios. The effect of the content of BA in the copolymer on the gel behaviors is discussed. The respective crosslinked copolymer exhibits a gel transition behavior, collapsing and shrinking above gel transition temperature but swelling and reexpanding below gel transition temperature. By utilizing this character, these copolymeric gels could be used for drug release or drug delivery systems. The drug released from the copolymeric gels was plotted as M-t/M-infinity versus t, where M-t/M-infinity is the fraction of drug released at given time t. In this experiment, crystal violet and caffeine were chosen as model drugs. The deswelling-kinetics experiments with caffeine showed that a water pocket was formed within the gel matrix when the gel deswelled rapidly.
Keywords:SIDE-CHAIN STRUCTURE;PHASE-TRANSITION;AQUEOUS-SOLUTIONS;POLY(N-ISOPROPYLACRYLAMIDE);DERIVATIVES