TITLE:
Morphology Control of Polymer Microspheres Containing Block Copolymers with Seed Polymerization
AUTHORS:
Hossein Taherzadeh, Shunsuke Sotowa, Kenji Ogino
KEYWORDS:
Microsphere, Morphology, Polymer Blend, Block Copolymer, Seed Polymerization
JOURNAL NAME:
Open Journal of Organic Polymer Materials,
Vol.5 No.2,
April
1,
2015
ABSTRACT: Microspheres based on binary polymer blend consisting of polystyrene (PSt), poly (methyl methacrylate)
(PMMA), block copolymer comprising PSt and PMMA subunits, and ternary polymer blend
consisting of PSt, PMMA, and block copolymer were fabricated by a solvent evaporation method, in
which a polymer solution in dichloromethane was dispersed in water phase with the aid of a homogenizer
to obtain an O/W emulsion followed by solvent evaporation with agitation to solidify
the polymer. In the case of ternary blend, the effect of block copolymer content on the morphology
of resulting spheres was investigated. Ternary blends afforded the bi-compartmental morphologies,
the intermediate morphology between Janus and core-shell, which was confirmed by TEM
observation. Seed polymerization of St or MMA was also carried out utilizing the resulting microspheres
as seed particles in order to control the shape, and the surface morphology of particles.
The particles with snowman-like morphology were obtained by seed polymerization of St using
PSt/PMMA binary blend microspheres as seed particles. Surface roughness was controlled by the
polymerization of MMA in the block copolymer seed, and that of St in the ternary blend seed.