Development of High Performance Polymer Blends

该研究项目的主要目标是开发基于聚乳酸（PLA）的生物聚合物共混物，具有优异的性能，以取代合成聚合物共混物，用于工程和可能的生物医学应用。我们将研究几种有前途的pla基共混物的性能，这些共混物由生物基聚酰胺（PA11）或聚己内酯（PCL），或可生物降解的聚丁二酸丁二酯（PBSA）和聚己二酸丁二酯（PBAT）制成。同时，将研究纳米颗粒添加到有前途的共混物中，以控制和稳定其形态并改善共混物的最终性能。潜在的纳米颗粒有纳米粘土（蒙脱土、海泡石、高岭土纳米管）、碳纳米管和石墨烯。将寻求纳米颗粒的选择性定位，特别是在两种聚合物组分的界面上。这些共混物和纳米复合材料将在不同的混合条件下通过内部混合器或使用小型双螺杆挤出机制备，并可能使用相容剂来降低聚合物组分之间的界面张力。最近提出的预测形态和流变特性演变的模型将被评估并最终修改以改进预测。纳米颗粒在每个聚合物组分中的分散质量和纳米颗粒-聚合物相互作用将通过线性粘弹性测量来评估，特别是使用表观屈服应力，这将与润湿系数相关。剪切和拉伸流动中的流变学将再次用于验证共混物和纳米复合材料形态的稳定性。将确定共混纳米复合材料的基本热力学、拉伸和冲击性能。最后，根据纳米颗粒的选择，电学或阻挡性能以及泡沫性将被评估。

The main objective of this research program is to develop biopolymer blends based on polylactide (PLA) with outstanding properties to replace synthetic polymer blends for engineering and possibly biomedical applications. We will examine the properties of a few promising PLA-based blends made with a bio-based polyamide (PA11) or polycaprolactone (PCL), or with biodegradable poly(butylene succinate adipate), PBSA, and poly(butylene adipate terephthalate), PBAT. In parallel, the addition of nanoparticles to promising blends will be investigated to control and stabilize their morphology and improve the final properties of the blends. Potential nanoparticles are nanoclay (montmorillonite, sepiolite, halloysite nanotubes), carbon nanotubes and graphene. Selective localization of the nanoparticles will be sought, in particular at the interface of both polymer components. These blends and nanocomposites will be prepared via an internal mixer or using a small twin-screw extruder under different mixing conditions and possibly using a compatibilizer to reduce the interfacial tension between the polymer components. Models recently proposed to predict the evolution of the morphology and rheological properties will be assessed and eventually modified to improve predictions. The quality of the nanoparticle dispersion in each polymer component and the nanoparticle-polymer interactions will be assessed through linear viscoelastic measurements, in particular using the apparent yield stress, which will be correlated to the wetting coefficient. Rheometry in shear and elongational flows will be used again to verify the stability of the blend and nanocomposite morphology. Basic thermo-mechanical, tensile and impact properties of the blend nanocomposites will be determined. Finally, depending on the nanoparticle choice, electrical or barrier properties as well as foamability would be evaluated.