Wang Kui, Peng Yong, Matadi Boumbimba Rodrigue, Bahlouli Nadia, Pessey Daniel, Ahzi Said, Addiego Frédéric, Rémond Yves
Key Laboratory of Traffic Safety on Track (Central South University) Ministry of Education, School of Traffic & Transportation Engineering, Central South University, Changsha 410075, China.
Joint International Research Laboratory of Key Technology for Rail Traffic Safety, Central South University, Changsha 410075, China.
Materials (Basel). 2019 Jul 29;12(15):2419. doi: 10.3390/ma12152419.
The effect of reprocessing on the quasi-static uniaxial tensile behavior of two commercial polypropylene (PP)-based composites is experimentally investigated and modeled. In particular, the studied materials consist of an unfilled high-impact PP and a talc-filled high-impact PP. These PP composites are subjected to repeated processing cycles, including a grinding step and an extrusion step to simulate recycling at the laboratory level, the selected reprocessing numbers for this study being 0, 3, 6, 9, and 12. Because the repeated reprocessing leads to thermo-mechanical degradation by chain scission mechanisms, the tensile behavior of the two materials exhibits a continuous decrease of elastic modulus and failure strain with the increasing amount of reprocessing. A physically consistent three-dimensional constitutive model is used to predict the tensile response of non-recycled materials with strain rate dependence. For the recycled materials, the reprocessing effect is accounted by incorporating the reprocessing sensitive coefficient into the constitutive model for Young's modulus, failure strain, softening, and hardening equations. Our predictions of true stress-true strain curves for non-recycled and recycled 108MF97 and 7510-are in good agreement with experimental data and can be useful for industries and companies which are looking for a model able to predict the recycling effect on mechanical behavior of polymer-based materials.
通过实验研究并建立了再加工对两种商用聚丙烯（PP）基复合材料准静态单轴拉伸行为的影响模型。具体而言，所研究的材料包括未填充的高抗冲PP和滑石粉填充的高抗冲PP。这些PP复合材料要经过反复的加工循环，包括研磨步骤和挤出步骤，以模拟实验室水平的回收利用，本研究选定的再加工次数为0、3、6、9和12。由于反复再加工会通过断链机制导致热机械降解，两种材料的拉伸行为表现出随着再加工量的增加，弹性模量和破坏应变持续下降。采用一个物理上一致的三维本构模型来预测具有应变率依赖性的未回收材料的拉伸响应。对于回收材料，通过将再加工敏感系数纳入杨氏模量、破坏应变、软化和硬化方程本构模型来考虑再加工效应。我们对未回收和回收的108MF97和7510的真应力-真应变曲线的预测与实验数据吻合良好，对于寻求能够预测回收利用对聚合物基材料力学行为影响模型的行业和公司可能会有所帮助。
