Thermoresponsive Interpolymeric Complex Assemblies from Co‐association of Linear PAAc Homopolymers with PNIPAAm Segments Containing PAAc‐Based Graft Copolymer
1. Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 300, Taiwan;2. Department of Chemical Engineering, National Chung Hsing University, Taichung 402, Taiwan;3. Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan
Abstract:
In aqueous solution at pH 3.0 and 20 °C, poly(acrylic acid)‐g‐poly(N‐isopropylacrylamide)/monomethoxy poly(ethylene glycol) (PAAc‐g‐PNIPAAm/mPEG) can assemble spontaneously with linear poly(acrylic acid) homopolymers (homoPAAc) into interpolymeric complexes (IPC). The resultant IPC assemblies exhibit a core–corona structure consisting of a hydrophobic PAAc/PNIPAAm complex core surrounded by hydrated PNIPAAm/mPEG coronas. At temperatures above 30 °C, the assemblies transform into a core–shell–corona micelle. Highly loose, irregular IPC assemblies developed at a reduced weight ratio of homoPAAc with the graft copolymer at 20 °C show particle size enlargement and structural variation above 30 °C. By contrast, co‐assembly of long homoPAAc chains with the copolymer leads to large aggregates comprising several IPC assemblies interconnected by homoPAAc chain segments.
