The aim of this study was to assess the physical phenomena that influence the rheological behaviour of polylactide/organo-modified clay nanocomposites. A model was proposed to explain the decrease in non-linear viscosity at high clay contents. Several variables were studied, including shear rate, temperature, clay volume fraction, and polymer molar mass. When the effects of the molar mass and temperature were separated from that of the clay volume fraction, the results suggested a decrease in viscosity compared with that of neat polylactide, which was mostly assigned to molar mass degradation and partially assigned to enhanced temperature dependency. The time–temperature superposition principle was employed for this purpose and highlighted two distinct trends in the activation energies with the clay volume fraction. Ultimately, rheological measurements were corroborated by morphological observations to reveal a non-monotonic evolution of viscosity with the clay volume fraction. These results help provide insight into simulation of the flow behaviour of a nanocomposite based on layered silicate.

中文翻译：

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聚乳酸纳米复合材料的非线性粘度随粘土体积分数的降低

本研究的目的是评估影响聚丙交酯/有机改性粘土纳米复合材料流变行为的物理现象。提出了一个模型来解释高粘土含量下非线性粘度的降低。研究了几个变量，包括剪切速率、温度、粘土体积分数和聚合物摩尔质量。当摩尔质量和温度的影响与粘土体积分数的影响分开时，结果表明与纯聚交酯相比粘度降低，这主要归因于摩尔质量降解，部分归因于温度依赖性增强。为此采用了时间-温度叠加原理，并强调了活化能与粘土体积分数的两种不同趋势。最终，流变测量结果通过形态观察得到证实，以揭示黏度随粘土体积分数的非单调演变。这些结果有助于深入了解基于层状硅酸盐的纳米复合材料的流动行为模拟。