Graft Copolymerization of Cinnamic Acid to Cassava Starch and its Viscosity Measurements

摘要

In this study, the modification of starch was conducted through graft copolymerization of cinnamic acid to result in starch-g-poly(cinnamic acid). The cinnamic acid polymerization was carried out via radical polymerization using cerium ammonium nitrate (CAN) as an initiator. The viscosity of the graft copolymer 10000 ppm dissolved in 16% NaOH solution was measured at a temperature range of 25-75 °C. The results showed that the higher the temperature the lower the viscosity. The activation energy of viscous flow for the copolymer was 18.4 kJ.mol-1. The viscosity values of the copolymer solutions were also measured in saline solutions with NaCl contents of 3-20%(w/v). For the measurements in these saline solutions, the highest viscosity was 3.39 cP at room temperature for the copolymer solution containing 5%(w/v) NaCl.