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Encapsulation of calcium carbonate by styrene polymerization
Author(s) -
Yang Yong,
Kong Xiang Zheng,
Kan Cheng You,
Sun Chang Gao
Publication year - 1999
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199901/02)10:1/2<54::aid-pat766>3.0.co;2-j
Subject(s) - materials science , monomer , polymerization , polystyrene , styrene , chemical engineering , polymer , calcium carbonate , emulsion polymerization , scanning electron microscope , polymer chemistry , copolymer , composite material , engineering
In order to obtain composites of calcium carbonate (CaCO 3 ) encapsulated by polystyrene (PS), soapless polymerization of styrene (S) in aqueous phase in the presence of CaCO 3 was carried out. Influences on the encapsulation and on monomer conversion were studied. Results showed that monomer conversion higher than 52% can be achieved by increasing the stirring speed of polymerization to 1000 rpm. In order to remove the polymer adsorbed on the surface of the inorganic powder, the crude PS/CaCO 3 composite obtained was treated by Soxhlet extractor, and the PS/CaCO 3 ratio after the extraction was measured and defined as the real encapsulation ratio. A maximum real encapsulation ratio of 6.4% was obtained regardless of variations in experimental conditions such as monomer/CaCO 3 ratios, monomer and initiator concentrations. The presence of PS on the surface of CaCO 3 was tested by scanning electron microscopy and zeta potential (ξ) measurement of CaCO 3 particles encapsulated by PS. With an increase in monomer conversion, ξ approached the value obtained from particles of pure PS prepared by soapless emulsion polymerization in the absence of CaCO 3 powder. Copyright © 1999 John Wiley & Sons, Ltd.