玉米淀粉在离子液体中流变学特性的研究

Study on rheological properties of corn starch in the ionic liquid

利用动态流变仪研究了玉米淀粉溶解在离子液体1-辛基-3-甲基咪唑氯盐([OMIM]Cl)中的流变学特性。结果表明:淀粉浓度4%、6%、8%的玉米淀粉-OMIMCl混合液均为非牛顿假塑性流体。淀粉浓度2%的玉米淀粉-OMIMCl混合液,其流体类型随温度的变化而改变。玉米淀粉在离子液体与水溶液中的溶胀方式比较相似。样品混合液的表观粘度随温度的升高而下降,随淀粉浓度的增加而增大。Arrhenius模型对混合液的流变特性具有较高的拟合度(R^2>0.9942)。在实验条件下,玉米淀粉-OMIMCl混合液不同程度地表现出了剪切稀化特性,且淀粉浓度越大,剪切稀化的程度越明显。

The theological properties of corn starch dissolved in the ionic liquid 1- octyl- 3- methylimidazolium chloride （[ OMIM] Cl）were investigated by a dynamic rheometer.The results showed that starch-OMIMCl mixtures which contained 4% ,6%,8% （w/w）corn starch were non-newtonian pseudoplastic fluids.While, the fluid type of 2% corn starch-OMIMCl mixtures varied with temperature.The corn starch swelled in ionic liquid in the same way as in aqueous solution.The apparent viscosity of samples were decreased with the increasing of temperature, and increased with the increasing of starch concentration.Rheologieal properties of the mixture were well described by An-henius model （R^2 〉 0.9942 ）.All the corn starch- OMIMCl mixtures exhibited shear-thinning behavior in varying degrees, under the experimental conditions.And the greater the concentration of starch was, the more obvious of shear thinning behavior.