Article

Facile, contolled, room-temperature RAFT polymerization of N-isopropylacrylamide

Department of Polymer Science, University of Southern Mississippi, Hattiesburg, Mississippi 39406, USA.
Biomacromolecules (Impact Factor: 5.75). 07/2004; 5(4):1177-80. DOI: 10.1021/bm049825h
Source: PubMed

ABSTRACT Poly(N-isopropyl acrylamide) is a thermoresponsive polymer that has been widely investigated for drug delivery. Herein, we report conditions facilitating the controlled, room-temperature RAFT polymerization of N-isopropylacrylamide (NIPAM). The key to success is the appropriate choice of both a suitable RAFT chain transfer agent (CTA) and initiating species. We show that the use of 2-dodecylsulfanylthiocarbonylsulfanyl-2-methyl propionic acid, a trithiocarbonate RAFT CTA, in conjunction with the room-temperature azo initiator 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), in DMF, at 25 degrees C, yields conditions leading to NIPAM homopolymerizations which bear all of the characteristics of a controlled/"living" polymerization. We also demonstrate facile size exclusion chromatographic analysis of PNIPAM samples in DMF at 60 degrees C, directly on aliquots withdrawn during the polymerizations, which avoids the problems previously reported in the literature.

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    • "observed that the use of the trithiocarbonate DMPA in conjunction with V-70 allowed for the synthesis of PNIPAM in a controlled fashion (Convertine et al., 2004). In our study, we also found that PNiPAAm had a narrow molecular weight distribution when synthesized in the presence of DMPA by gamma radiation. "
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