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首先将纤维素纳米晶体(CNC)悬浮液进行超声分散,然后与壳聚糖乙酸溶液进行高速搅拌共混,制备不同CNC含量的壳聚糖-CNC共混均匀溶液。采用平板式旋转流变仪研究了CNC含量对壳聚糖溶液流变行为的影响。测试结果表明:壳聚糖-CNC共混溶液表现为非牛顿流体行为;黏度随温度的上升而下降,但在高剪切速率范围内,温度对黏度的影响不再明显;随着CNC含量的增加,壳聚糖溶液的表观黏度增大,对剪切速率的敏感性增强,同时非牛顿指数和黏流活化能降低;共混原液的结构黏度指数随CNC含量减少以及温度升高而降低;壳聚糖-CNC共混溶液储能模量和损耗模量的交叉点随温度的升高向高频区移动,随CNC含量的增加向低频区移动,溶液流变规律基本符合Cox-Merz规则。
Firstly, the cellulose nanocrystal (CNC) suspension was ultrasonically dispersed, and then chitosan acetic acid solution was mixed with high speed stirring to prepare chitosan-CNC blending solution with different CNC contents. The effect of CNC content on the rheological behavior of chitosan solution was investigated by a flat-plate rotary rheometer. The results show that the chitosan-NC solution shows non-Newtonian fluid behavior. The viscosity decreases with increasing temperature. However, the effect of temperature on viscosity is no longer obvious at high shear rate. With the increase of the content of CNC The apparent viscosity of chitosan solution increases and its sensitivity to shear rate increases, while the non-Newtonian index and viscous flow activation energy decrease. The structural viscosity index of the blend solution decreases with the decrease of CNC content and temperature ; The intersection of the storage modulus and the loss modulus of the chitosan-CNC solution moves to high frequency region with the increase of temperature, and moves to the low frequency region as the CNC content increases, and the solution rheology basically conforms to Cox-Merz rule.