Control of thermoresponsive property of urea end-functionalized poly(n-isopropylacrylamide) based on the ydrogen bond-assisted self-assembly in water
Journal
Journal of Polymer Science, Part A: Polymer Chemistry
Journal Volume
47
Journal Issue
22
Pages
6259-6268
Date Issued
2009
Author(s)
Abstract
Abstract The precise synthesis and variation in the thermoresponsive property based on the supramolecular assembly of a novel urea end‐functionalized poly( N ‐isopropylacrylamide) (PNIPAM) were studied. A series of PNIPAMs with different diphenylurea groups at the chain end (XPhNHCONHPhtrzPNIPAM: X = H, OCH 3 , CH 3 , NO 2 , Cl, and CF 3 ) were synthesized by using a combination of the atom transfer radical polymerization and the copper(I)‐catalyzed azide‐alkyne cycloaddition. The cloud point of the obtained polymers depended on the hydrogen‐bonding ability of the introduced urea group. The 1 H NMR measurement suggested that the obtained PNIPAM assembled in water via the intermolecular hydrogen bonding by the terminal urea group. From the dynamic light scattering and transmission electron microscopy measurements, the aggregated nanoparticles of the resulting polymer were directly observed in water at a temperature below its cloud point. The hydrogen‐bonding property of the chain end urea group was concluded to be involved in the aggregation of the PNIPAM in water, leading to the variation in its cloud point. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6259–6268, 2009
SDGs
Type
journal article