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To carry out miniemulsion polymerization of styrene in the presence of carbon black, carbon black was hydroxylated using potassium permanganate with the aid of a phase transfer catalyst, tetrabutyl ammonium bromide (TBABr). The hydroxylated carbon black was further reacted with oleic acid. The surface modification of carbon black with oleic acid was confirmed by FTIR, XPS, and TEM. The oleic acid-coated carbon black was successfully microencapsulated by polystyrene using miniemulsion polymerization. Polymerization failed when pristine carbon black was used. However, satisfactory conversion (> 96%) was achieved using the oleic acidmodified carbon black. The existence of a polystyrene layer was confirmed by TEM. In contrast the pristine carbon black, the oleic acid-coated carbon black did not act as a radical scavenger during polymerization.

Amphiphilic copolymer microspheres of poly(styrene-co-4-vinylpyridine) were prepared by dispersion polymerization in an alcohol/water medium. The synthesis of poly(styrene-co-4-vinylpyridine) microparticles was successfully carried out, and the latexes had a spherical morphology with good monodispersity. The degree of conversion in the early stage of polymerization decreased with increasing 4-vinylpyridine (4VP) monomer content, but the final conversions were similar (>95%). The copolymerization rate decreased with increasing 4VP content, and a broad particle size distribution was observed with 20 wt % 4VP because of the prolonged nucleation time. With the 4VP concentration increasing, the molecular weight of the copolymer microspheres decreased, and the glass-transition temperature of the copolymers increased; this indicated that all the copolymers were random and homogeneous.

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