Synthesis and characterization of thermally-responsive hydroxypropyl methylcellulose gel beads

✍ Scribed by Stephen M. O'Connor; Stevin H. Gehrke

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 175 KB
• Volume: 66
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19971114)66:7<1279::aid-app7>3.0.co;2-d

✦ Synopsis

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 25ЊC 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 75ЊC. The spherical beads were made in diameters ranging from 500 to 3000 mm. 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.