Aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA) at 70oC is conducted via reversible addition-fragmentation chain transfer (RAFT) chemistry using a poly(glycerol monomethacrylate)-based chain transfer agent.  Gel permeation chromatography analyses confirm that the diblock copolymer chains have relatively low polydispersities (Mw/Mn < 1.20) even at HPMA conversions above 99%, which indicates well-controlled polymerizations and high blocking efficiencies. For a fixed PGMA block, systematically increasing the target degree of polymerization of the core-forming PHPMA block leads to the formation of pure phases of spheres, worms or vesicles directly in water at 10 % solids. Such morphological changes are dictated by changes in the interfacial curvature during the HPMA polymerization. The block copolymer worms form an aqueous gel phase, presumably due to inter-worm entanglements. The properties of these gels can be tuned by varying the worm width and worm length. Since both PGMA and PHPMA are biocompatible, such gels may have biomedical applications.

Polymerization-induced self-assembly via RAFT aqueous dispersion polymerization

242nd National Meeting (2011)

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