微晶纤维素/聚丁二酸丁二醇酯复合材料的流变行为

Rheological behavior of microcrystalline cellulose/poly(butylene succinate)composites

采用熔融共混法制备了微晶纤维素/聚丁二酸丁二醇酯(MCC/PBS)复合材料,用高级毛细管流变仪和旋转流变仪分别测定复合材料的稳态流变性能和动态流变性能,研究了不同MCC含量、不同温度对复合材料流变行为的影响。结果表明,复合材料的黏度与剪切速率的流变曲线符合幂律流体的特征,可以用幂律模型对其进行拟合;复合材料的黏度与温度的关系可用Arrhenius方程对其进行描述。在线性黏弹区,复合材料的储能模量(G′)维持恒定,当应变(γ)超过临界值(γ_c)时,复合材料进入非线性黏弹区,出现了"Payne"效应,并且随着MCC含量的增加,γ_c下降。在角频率(ω)扫描范围内,复合材料的储能模量(G′)、损耗模量(G″)和复数黏度|η*|均随着MCC含量的增加而增大。在相同的MCC含量下,G″的值始终大于G′的值,损耗因子(tanδ)均大于1。在低频区,G′出现第二平台。MCC/PBS复合材料加工流变特性的研究,对指导MCC/PBS复合材料的成型加工具有一定的价值。

The microcrystalline cellulose（MCC）and poly（butylene succinate）（PBS）composites were prepared by melt blending method.The influence of different temperature and MCC content on the steady-state rheological behavior and dynamic rheological behavior of the composites was studied by advanced capillary rheometer and rotationnal rheometer.The results show that：the rheological behavior of the corresponding relationship between the viscosity and the shear rate of the composites fits the power law model.Arrhenius equation can be employed to describe the dependence of the viscosity on temperature.The storage modulus（G′）of the composites keeps invariant in linear viscoelastic region.When strain（γ）is over critical value（γc）,the composites enter into the nonlinear viscoelastic region and the＂Payne effect＂occur.Theγcdecrease rapidly with the increase of strain.The storage modulus（G′）,loss modulus（G″）and complex viscosity（｜η＊｜）of the composites all increase with the increasing contents of MCC in the range of angular frequency（ω）scanning.The value of G″is always higher than G′and the value of loss factor（tan（δ））is always greater than one under the condition of the invariable content of MCC.Second plateau is observed for G′at lowω.The study of processing rheological properties of MCC/PBS composites might be valuable for the processing of MCC/PBS composites.