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Synthesis of polymeric microspheres employing SPG emulsification technique
Author(s) -
Omi Shinzo,
Katami Ken'ichi,
Yamamoto Arihiro,
Iso Mamoru
Publication year - 1994
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/app.1994.070510101
Subject(s) - monomer , microporous material , chemical engineering , dispersity , suspension polymerization , materials science , polystyrene , polymer chemistry , membrane emulsification , polymerization , heptane , nucleation , particle (ecology) , permeation , particle size , polymer , membrane , chemistry , microsphere , composite material , organic chemistry , oceanography , biochemistry , engineering , geology
Relatively uniform polymeric microspheres, the coefficients of variation being close to 10%, were obtained by the BPO‐initiated suspension polymerization of styrenic monomers. Unlike the conventional stirred‐tank system, a particular microporous glass membrane (SPG) provided uniform monomer droplets continuously when monomer was allowed to permeate through the micropores. The monomer droplets were suspended in an aqueous solution containing the stabilizing agents, transferred to a stirred vessel, and polymerized. Up to 10μm spheres, of a far narrower size distribution than those obtained by conventional microsuspension polymerization spheres, were obtained. The initial droplet size and distribution were retained with the successful suppression of secondary particle nucleation by the addition of hydroquinone in the aueous phase. Crosslinked polystyrene spheres were also synthesized in the presence of various low‐molecular‐weight diluents. While a good solvent, toluene, was not so effective; poor solvents, n ‐heptane and n ‐heptane, easily yielded the microporous structure, the specific surface area being as high as 160 m 2 /g. © 1994 John Wiley & Sons, Inc.