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Synthesis and characterization of thermally‐responsive hydroxypropyl methylcellulose gel beads
Author(s) -
O'Connor Stephen M.,
Gehrke Stevin H.
Publication year - 1997
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19971114)66:7<1279::aid-app7>3.0.co;2-d
Subject(s) - swelling , materials science , suspension (topology) , bead , chemical engineering , polymer , volume (thermodynamics) , phase (matter) , polymer chemistry , particle size , particle (ecology) , aqueous solution , composite material , chemistry , organic chemistry , physics , mathematics , oceanography , quantum mechanics , homotopy , pure mathematics , engineering , geology
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°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°C. The spherical beads were made in diameters ranging from 500 to 3000 μ. 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. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1279–1290, 1997