Preparation and characterization superporous hydroxypropyl methylcellulose gel beads

Stearic acid monoglyceride as suspension agent, divinylsulfone (DVS) as the crosslinker, cyclohexane as the continuous organic phase and nano-calcium carbonate as the porogen were used to produce hydroxypropyl methylcellulose (HPMC) porous gels in bead form by inversing phase suspension crosslinking. Effects of porogen dosage on the gel surface and inner morphology, density, porosity, swelling kinetics have been studied. Results show that the interpenetrate pores can be formed in gel beads when the porogen dosage reached 70 wt% of the dry HPMC. The equilibrium swelling ratios of the gel beads increased from 30.1 (g/g) to 37.4 (g/g) when the fraction of CaCO3 dosage increased from 0 to 100 wt% of the dry HPMC and the equilibrium swelling time of the gels decreased from about 400 to 20 min. The results also show that the gel re-swelling capability is related to the porous structure.