Mechanistic study of the formation of amphiphilic core-shell particles by grafting methyl methacrylate from polyethylenimine through emulsion polymerization

Ho, Kin Man, Li, Wei Ying, Lee, Cheng Hao, Yam, Chun Ho, Gilbert, Robert G. and Li, Pei (2010) Mechanistic study of the formation of amphiphilic core-shell particles by grafting methyl methacrylate from polyethylenimine through emulsion polymerization. Polymer, 51 15: 3512-3519. doi:10.1016/j.polymer.2010.05.035


Author Ho, Kin Man
Li, Wei Ying
Lee, Cheng Hao
Yam, Chun Ho
Gilbert, Robert G.
Li, Pei
Title Mechanistic study of the formation of amphiphilic core-shell particles by grafting methyl methacrylate from polyethylenimine through emulsion polymerization
Journal name Polymer   Check publisher's open access policy
ISSN 0032-3861
1873-2291
Publication date 2010-07-08
Sub-type Article (original research)
DOI 10.1016/j.polymer.2010.05.035
Volume 51
Issue 15
Start page 3512
End page 3519
Total pages 8
Place of publication Kidlington, Oxford, United Kingdom
Publisher Elsevier
Collection year 2011
Language eng
Abstract The mechanism for the formation of amphiphilic core–shell particles in water is elucidated via a kinetic study of semi-batch polymerization of methyl methacrylate (MMA) grafted from polyethylenimine (PEI) initiated with tert-butyl hydroperoxide in an emulsion polymerization. The monomer conversion, the polymerization kinetics, the particle size, the particle number density, the poly(methyl methacrylate) (PMMA) core diameter, the percentage of unbound PEI, and the grafting efficiency of PMMA were determined at various times during the polymerization. The particle number density and the percentage of unbound PEI were almost independent of the controllable variables. The particle sizes and the core diameters increased with each consecutive batch of monomer addition, while the grafting efficiency of PMMA decreased. These data supported the hypothesis that the PEI-g-PMMA graft copolymers were formed early in the polymerization and later self-assembled to a new phase, micellar microdomains. These microdomains act as loci for subsequent MMA polymerization as the monomer is fed into the reaction, without subsequent formation of new particles. The size of the resulting highly uniform core–shell particles (99–147 nm) can be controlled by choosing the amount of monomer charged. Thus, this polymerization method is viable for a large scale production of core–shell particles with high solids content. Copyright © 2010 Elsevier Ltd All rights reserved.
Keyword Polyethylenimine
Graft polymerization
Amphiphilic core-shell particles
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2011 Collection
School of Agriculture and Food Sciences
Centre for Nutrition and Food Sciences Publications
 
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Created: Sun, 25 Jul 2010, 00:02:55 EST