Optimized Swelling Properties of Hydrogels Based on Poly(Vinyl Alcohol)-Carrageenan

Hydrogels materials have been widely used in controlled delivery systems. The hydrogels were prepared successfully by dissolving carrageenan (C) in 1% NaOH 0.5 M and poly(vinyl alcohol) (PVA) while stirring it for 20 minutes. This work aim is to characterize the swelling properties hydrogel include the effect of weight ratio, plasticizer, heating time and temperature process. The solution was heated at 70 degrees C for 4 hours before being washed using ethanol and kept in NaOH 0.5 M for 1 hour. The hydrogel was obtained by drying the mixture at 60 degrees C for 24 hours. The percentage of swelling ratio was determined through weight difference method. The results showed that the optimum weight ratio of C/PVA on the swelling ratio was 1.1 g/g. The swelling ratio of hydrogel using polyglycerol as plasticizer was significantly higher than that of using glycerol. The longer the heating time of the cross-linked could reduce the swelling ratio. The process temperature did not affect the swelling ratio.