Preparation of P4VP-g-PSt Copolymer Microspheres with Controllable Size by Atom Transfer Radical Polymerization Synthesi
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,CuCI as catalyst and tris[2-(dimethylamino)ethyl]amine (Me_6TREN) as ligand in 2-propanol. The structure of St-P4VP macromonomer was identified by proton nuclear magnetic resonance (~1H 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 ℃.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.
作 者： HU, Na NI, Zhongbin CHU, Hong LIU, Xiaoya CHEN, Mingqing 作者单位： School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, China 刊 名： 中国化学（英文版） SCI 英文刊名： CHINESE JOURNAL OF CHEMISTRY 年，卷(期)： 2009 27(11) 分类号： O6 关键词： poly(4-vinylpyridine) macromonomer dispersion copolymerization microsphere