Preparation, characterization and rheological behavior of water-swellable polymers

Abstract Ionic biopolymer hydrogels were prepared by the cross-linking of starches with 
sodium trimetaphosphate in alkaline medium at 40 C for 2 hours. The swelling capacity is 
relatively high—up to 310 g H 2 0/g polymer. Salt solutions have a marked influence, and 
result in shrinkage but not in a total collapse. The effect of both the cross-linker and substrate 
concentrations on the swelling and rheological properties was investigated. The influence of 
temperature and NaOH concentration on the rheological behaviour suggests that they are ...