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Preparation of P4VP‐ g ‐PSt Copolymer Microspheres with Controllable Size by Atom Transfer Radical Polymerization Synthesized Poly(4‐vinylpyridine) Macromonomer
Author(s) -
Hu Na,
Ni Zhongbin,
Chu Hong,
Liu Xiaoya,
Chen Mingqing
Publication year - 2009
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.200990377
Subject(s) - macromonomer , atom transfer radical polymerization , polymer chemistry , chemistry , copolymer , polymerization , gel permeation chromatography , styrene , molar mass distribution , dispersion polymerization , polymer , organic chemistry
Poly(4‐vinylpyridine) macromonomer (St‐P4VP) with a styryl end group was synthesized by atom transfer radical polymerization (ATRP) of 4‐vinylpyridine using p ‐(chloromethyl)styrene (CMSt) as functional initiator, CuCl as catalyst and tris[2‐(dimethylamino)ethyl]amine (Me 6 TREN) as ligand in 2‐propanol. The structure of St‐P4VP macromonomer was identified by proton nuclear magnetic resonance ( 1 H NMR). The result of gel permeation chromatography (GPC) illustrated that the number‐average molecular weight of St‐P4VP could be controlled by adjusting polymerization conditions. Poly(4‐vinylpyridine) grafted polystyrene microspheres (P4VP‐ g ‐PSt) were then prepared by dispersion copolymerization of styrene with St‐P4VP macromonomers. The effects of polymerization reaction parameters such as medium polarity, concentration of St‐P4VP macromonomer and polymerization temperature on the sizes and size distribution of P4VP‐ g ‐PSt microspheres were investigated. The results of transmission electron microscopy (TEM), scanning electron microscopy (SEM) and laser light scattering (LLS) indicated that mono‐dispersed P4VP‐ g ‐PSt microspheres with average diameters of 100–200 nm could be obtained when the molar ratio of St to St‐P4VP was 0.25:100 in ethanol/water mixed solvents ( V / V =80:20) at 60°C. Such kind of graft copolymer microspheres was expected to be applied to many fields such as drug delivery system and protein adsorption/separation system due to their particular structure.