Synthesis of end-functionalized poly( N-isopropyl acrylamide) with zinc porphyrin and its photocatalytic activity under visible light.

ABSTRACT A series of well-defined linear poly( N-isopropyl acrylamide) with an asymmetrical zinc(II) porphyrin (ZnPor-PAM) end group was synthesized by atom transfer radical polymerization, wherein 5,10,15,20- tetra( p-bromopropanoyloxyethylphenyl) zinc porphyrin tripropionate was used as the initiator and CuBr/tris(2-dimeoethyl)amine was used as the catalyst system. The structure of the ZnPor-PAM was characterized by Fourier transform infrared spectroscopy and ¹H-NMR. In addition, the polydispersity index (PDI) obtained by gel permeation chromatography indicated that the molecular weight distribution was narrow; thus, the polymerization was well controlled (1.05 < PDI < 1.21). Because of the incorporation of hydrophobic porphyrin, the lower critical solution temperature of ZnPor-PAM was lower than that of the N-isopropyl acrylamide homopolymer. Most interestingly, the ZnPor-PAM possessed remarkable photocatalytic activity for the oxidative degradation of methylene blue in the presence of hydrogen peroxide under visible-light radiation. Moreover, ZnPor-PAM could be reused through the uncomplicated procedure, which exploited the thermoresponsive properties of ZnPor-PAM without any significant loss in activity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40523. [ABSTRACT FROM AUTHOR]