Narrow or Monodisperse, Highly Cross-Linked, and 鈥淟iving鈥?Polymer Microspheres by Atom Transfer Radical Precipitation Polymerization
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- 作者：Jingshuai Jiang ; Ying Zhang ; Xianzhi Guo ; Huiqi Zhang
- 刊名：Macromolecules
- 出版年：2011
- 出版时间：August 9, 2011
- 年：2011
- 卷：44
- 期：15
- 页码：5893-5904
- 全文大小：1021K
- 年卷期：v.44,no.15(August 9, 2011)
- ISSN：1520-5835
文摘
A facile, general, and efficient one-pot approach to obtaining narrow or monodisperse, highly cross-linked, surface-functionalized, and 鈥渓iving鈥?polymer microspheres with uniformly cross-linked structures by atom transfer radical precipitation polymerization (ATRPP) is described for the first time. The simple introduction of atom transfer radical polymerization (ATRP) mechanism into precipitation polymerization system allows the direct generation of uniformly cross-linked 鈥渓iving鈥?polymer microspheres with their number-average diameters ranging from 0.73 to 3.25 渭m and their polydispersity indices being typically lower than 1.01. The polymerization parameters (including stirring rate, monomer loading, initiator and catalyst concentrations, molar ratio of cross-linker to monovinyl functional comonomer, and polymerization scale and time) have proven to show significant influence on the morphologies of the resulting polymer microspheres, which makes it very convenient to control the particle sizes by easily tuning the reaction conditions. The general applicability of ATRPP was demonstrated by synthesizing a series of uniform functional copolymer microspheres with different incorporated functional comonomers (i.e, 4-vinylpyridine, acrylamide, and 2-hydroxyethyl methacrylate). Moreover, the 鈥渓ivingness鈥?of the resulting polymer microspheres was confirmed by their direct grafting of hydrophilic polymer brushes via surface-initiated ATRP under mild reaction conditions. Furthermore, a 鈥済rafting from鈥?particle growth mechanism is proposed for ATRPP, which is considerably different from the 鈥済rafting to鈥?particle growth mechanism in the traditional precipitation polymerization.