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Emulsion polymerization of styrene with amphiphilic random copolymer as surfactant: Predominant droplet nucleation
Author(s) -
Liu Li,
Liu XiaoLi,
Han Ye,
Chen QingRui,
Yu JingFeng,
Liu FengQi
Publication year - 2009
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.30483
Subject(s) - polymerization , copolymer , polymer chemistry , emulsion polymerization , monomer , styrene , nucleation , materials science , pulmonary surfactant , precipitation polymerization , chemical engineering , chain growth polymerization , solution polymerization , radical polymerization , chemistry , polymer , organic chemistry , composite material , engineering
Amphiphilic random copolymer consisting of monomeric units of poly (butyl acrylate) and poly (maleic acid salt) was synthesized and characterized. The emulsion polymerization kinetics of styrene stabilized by this copolymer was investigated. The influencing factors, including polymeric surfactant concentration, initiator concentration and polymerization temperature, were systematically studied. The kinetic data show that the polymerization rate ( R P ) increased with the increase of the polymeric surfactant concentration ([S]) and polymerization temperature ( T ). At the higher [S], droplets nucleation and micelle nucleation coexisted in the polymerization system; at the lower [S], only the droplets nucleation process existed. The polymerization did not follow Smith‐Ewart Case II kinetics. Dynamic light scatter and transmission electron microscope were utilized to measure the sizes and shapes of the particles, respectively. It would be speculated that a kind of large heterogeneous particles with multiple‐active‐sites was formed in the polymerization system. The increasing of R P with increasing initiator concentration ([KPS]) was rapid at a medium [KPS], but the slowly increasing was observed at a lower or higher [KPS]. It was attributed to the barrier effect of the polymeric surfactant around the monomer droplets. The polymerization activation energy was 60.29 kJ/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009