SYNTHESIS AND CHARACTERIZATION OF THERMALLY-RESPONSIVE HYDROXYPROPYL METHYLCELLULOSE GEL BEADS

摘要

Thermally responsive gels of hydroxypropyl methylcellulose (HPMC) were produced in spherical form by a suspension crosslinking technique. The suspension crosslinking of HPMC with divinylsulfone was accomplished by dispersing aqueous polymer droplets, containing all of the reactants, in a continuous organic phase. The gel beads were characterized in terms of their swelling properties and particle size distribution. The swelling degrees at 25 degrees C of different formulations of the gel beads ranged from 12 to 123 times their dry volume and shrank to 4 to 18 times dry volume at 75 degrees C. The spherical beads were made in diameters ranging from 500 to 3000 mu m. Bead size generally decreased with use of a larger impeller, suspending at high stirring speeds, or at a lower phase ratio. As bead size decreased, the size distribution also narrowed. When compared with bulk HPMC gels, the gel beads demonstrated the same swelling properties and crosslinked network formation. (C) 1997 John Wiley & Sons, Inc. [References: 34]