Time-resolved gel permeation chromatographic study on poly(N- isopropylacrylamide)-block-poly(ethylene glycol) prepared by soap-free emulsion polymerization

Ryuhei Motokawa, Takayuki Nakahira, Masahiko Annaka, Takeji Hashimoto, Satoshi Koizumi

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

To synthesize an amphiphilic block copolymer of poly(N-isopropylacrylamide) -block-poly(ethylene glycol) (NE), an aqueous soap-free emulsion polymerization system was employed where poly(N-isopropylacrylamide) (PNIPA), polymerized from the radically activated chain ends of poly(ethylene glycol) (PEG), forms micelle cores stabilized by PEG brush chains emanating there from. When this polymerization was carried out at temperatures equal to or higher than 34°C, narrowly-dispersed NE, which cannot be obtained by solution polymerization, was successfully obtained. To elucidate the living nature of the soap-free emulsion polymerization, time-dependent monomer conversion and molecular weight of NE was investigated by time-resolved gel permeation chromatography (GPC). The results indicate that the compartmentalization of end radicals into micelles cores leads to the quasi-living behavior of the polymerization.

Original languageEnglish
Pages (from-to)9019-9022
Number of pages4
Journalpolymer
Volume45
Issue number26
DOIs
Publication statusPublished - Dec 2004

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Materials Chemistry

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