Jump to main content
Jump to site search

Issue 19, 2015
Previous Article Next Article

Synthesis and thermoresponsive properties of four-arm star-shaped poly(N-isopropylacrylamide)s bearing covalent and non-covalent cores

Author affiliations

Abstract

The present study describes the precise synthesis and thermoresponsive properties of two types of four-arm star-shaped poly(N-isopropylacrylamide)s (PNIPAM), i.e., the covalently linked one (3) and the non-covalently Ru(II)-chelated one (5). The atom transfer radical polymerization (ATRP) method was used to prepare the azido-terminated PNIPAM (1) arm using (2-azidoethyl)-2-chloropropionamide (AECP) as the initiator. 3 was subsequently prepared based on the click reaction of 1 with a multifunctional linker of tetra[(5-hexynyloyloxy)methyl]methane. For comparison, its linear counterpart 2 was also synthesized as a reference polymer by the same method using ethyl 5-hexynyloate. The four-arm star-shaped PNIPAM Ru complex 5, on the other hand, was prepared by a click-to-chelate approach, which involves the click reaction of 1 with 2,6-diethynylpyridine to produce the macroligand of 2,6-bis(1-PNIPAM-1,2,3-triazol-4-yl)pyridine (4) and the chelating reaction of RuCl3 with 4 to afford 5. The thermoresponsive properties of the resulting polymers were investigated using a UV-vis spectrophotometer by measuring the optical transmittance of the polymer solution with varying solution temperature and the cloud point (Tc) at 50% transmittance intensity in order to assess their thermoresponsive properties. The detailed thermoresponsive properties of these polymers, including the effects of the polymer terminal and core linkage and constituents of the four-arm star-shaped PNIPAMs on the Tc, are significantly described in the later part of this study.

Graphical abstract: Synthesis and thermoresponsive properties of four-arm star-shaped poly(N-isopropylacrylamide)s bearing covalent and non-covalent cores

Back to tab navigation

Supplementary files

Publication details

The article was received on 20 Feb 2015, accepted on 19 Mar 2015 and first published on 23 Mar 2015


Article type: Paper
DOI: 10.1039/C5PY00277J
Author version available: Download Author version (PDF)
Citation: Polym. Chem., 2015,6, 3608-3616
  •   Request permissions

    Synthesis and thermoresponsive properties of four-arm star-shaped poly(N-isopropylacrylamide)s bearing covalent and non-covalent cores

    Y. Chen, N. Xiao, M. Fukuoka, K. Yoshida, Q. Duan, T. Satoh and T. Kakuchi, Polym. Chem., 2015, 6, 3608
    DOI: 10.1039/C5PY00277J

Search articles by author

Spotlight

Advertisements