Synthesis and characterization of temperature-responsive poly(vinyl alcohol)-based copolymers

Authors

  • Yuanfeng Pan,

    1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China
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  • Huining Xiao,

    Corresponding author
    1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China
    2. Department of Chemical Engineering, University of New Brunswick, Fredericton, New Brunswick E3B 5A3, Canada
    • State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China
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  • Guanglei Zhao,

    1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China
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  • Beihai He

    1. State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China
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Abstract

A poly(vinyl alcohol) (PVA)/sodium acrylate (AANa) copolymer was synthesized to improve the water solubility of PVA at the ambient temperature. Furthermore, a series of temperature-responsive acetalyzed poly(vinyl alcohol) (APVA)-co-AANa samples of various chain lengths, degrees of acetalysis (DAs), and comonomer contents were prepared via an acid-catalysis process. Fourier transform infrared and 1H-NMR techniques were used to analyze the compositions of the copolymers. The measurement of the turbidity change for APVA-co-AANa aqueous solutions at different temperatures revealed that the lower critical solution temperature (LCST) of the copolymers could be tailored through the control of the molecular weight of the starting PVA-co-AANa, DA, and comonomer ratios. Lower LCSTs were observed for APVA-co-AANa with a longer chain length, a higher DA, and fewer acrylic acid segments. In addition, the LCSTs of the APVA-co-AANa aqueous solutions appeared to be salt-sensitive. The LCSTs decreased as the concentration of NaCl increased. Moreover, atomic force microscopy images of APVA-co-AANa around the LCST also proved the temperature sensitivity. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

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