Redox polymerization of N-isopropylacrylamide by using hydroxylated soya oil polymer


Abstract: Water soluble hydroxylated soya oil polymer was used in the redox polymerization of N-isopropylacrylamide (NIPAM) in order to obtain water-based hydroxylated-soya oil polymer-g-PNIPAM graft copolymer. For this purpose, soya oil was exposed to air under sunlight to obtain autoxidized soya oil polymer (PSy-ox). PSy-ox was allowed to react with diethanol amine to obtain hydroxylated soya oil polymer (hydroxylated-PSy). An ammonium persulfate with hydroxylated-PSy redox initiating system was used in the polymerization of NIPAM in order to obtain thermo-responsive hydroxylated-PSy-g-PNIPAM water-based graft copolymers. The graft copolymers were characterized using proton nuclear magnetic resonance, Fourier transform infrared~spectroscopy, gel permeation chromatography, thermal gravimetric analysis, and differential scanning calorimetry techniques. The effects of hydroxylated-PSy on the thermal response rate of PNIPAM and the percentage of transmittance in the water of graft copolymers were studied by means of observing UV transmittance behaviors in response to changing temperature. This showed the temperature-responsive property, and exhibited a volume phase transition from 22 °C to 29 °C, while that of PNIPAM was 32 °C.

Keywords: Hydroxylated soya oil polymer, thermo-responsive polymer, N-isopropylacrylamide, redox polymerization

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