【摘要】 利用激光光散射仪表征了蜡状谷物支链淀粉和土豆支链淀粉在浓度为0.5 mol/L的NaOH水溶液中的重均相对分子质量(Mw)、根均方旋转半径(<Rg>)和第二维利系数(A2),通过这些分子参数计算了蜡状谷物支链淀粉和土豆支链淀粉的临界交叠浓度.系统地研究了支链淀粉在稀溶液和半稀溶液中的流动行为,讨论了剪切速率、浓度、温度等对溶液表观黏度(aη)、流动指数(n)、零切黏度(0η)等的影响.结果表明,蜡状谷物支链淀粉在NaOH水溶液中表现为非牛顿型流体,且随着浓度增加,非牛顿性增强;而土豆支链淀粉即使在临界交叠浓度以上也表现为牛顿型流体.更多还原

【Abstract】 The average molecule weight(Mw),gyration radius(<Rg>) and second vitrial coefficient(A2)of wax corn amylopectin and potato amylopectin was characterized by static laser light scattering.Besides,the rheological behavior in dilute and semidilute NaOH solution were investigated by Rheometer.Furthermore,the influence of shear rate,polymer concentration and the temperature on the apparent viscosity,flow index and zero-shear viscosity was studied.It was found that the wax corn amylopectin in NaOH solution were non-Newton fluid and non-Newton fluid property become obvious with increase of concentration,whereas potato amylopectin was Newton fluid even though it is beyond the critical overlap concentration(c*)更多还原