Aggregation behaviour of well defined amphiphilic diblock copolymers with poly (N-isopropylacrylamide) and hydrophobic blocks

被引：143

作者：

Nuopponen, M ^{[1
]}

Ojala, J ^{[1
]}

Tenhu, H ^{[1
]}

机构：

[1] Univ Helsinki, Dept Chem, Polymer Chem Lab, FIN-00014 Helsinki, Finland

来源：

POLYMER | 2004年 / 45卷 / 11期

关键词：

diblock copolymers; polymeric micelles; controlled radical polymerization;

D O I：

10.1016/j.polymer.2004.03.083

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Series of amphiphilic diblock copolymers with poly(N-isopropylacrylamide) as a hydrophilic block and a hydrophobic block consisting of either polystyrene or poly(tert-butyl methacrylate) were synthesised using RAFT polymerisations. Differential scanning calorimetry showed the chemically different blocks being phase separated in dry polymers. Light scattering and microcalorimetry studies were performed on aqueous solutions to investigate the phase behavior of the diblock copolymers. By carefully transferring the polymers from an organic solvent to water. either micellar particles or large aggregates were obtained depending on the relative lengths of the blocks. Large aggregates collapsed upon heating. whereas collapse occurred slowly within a broad temperature range in the case of micelle like structures. However, microcalorimetrically the collapse of the PNIPAM chains was observed to take place in all samples, suggesting that the shells of the micellar particles are crowded in a way which hinders the compression of the poly(N-isopropylacrylamide) chains. (C) 2004 Elsevier Ltd. All rights reserved.

引用

页码：3643 / 3650

页数：8

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