Title

Facile, Controlled, Room-Temperature RAFT Polymerization of N-isopropylacrylamide

Document Type

Article

Publication Date

7-1-2004

Department

Polymers and High Performance Materials

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 degreesC, 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facile size exclusion chromatographic analysis of PNIPAM samples in DMF at 60 degreesC, directly on aliquots withdrawn during the polymerizations, which avoids the problems previously reported in the literature.

Publication Title

Biomacromolecules

Volume

5

Issue

4

First Page

1177

Last Page

1180