Development of high performance PLA based nanocomposites

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，该聚合物具有优异的性能，可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其最终性能。潜在的纳米颗粒有纤维素纳米晶体（cnc）、纳米粘土（蒙脱土、海泡石、高岭土纳米管）、碳纳米管和石墨烯。将确定潜在纳米复合材料和聚合物组分的不同组分之间的汉森溶解度参数差异，并将其与从流变学中确定的表观屈服应力相关联。这些结果将用于选择最有前途的纳米复合材料的组分。将寻求纳米颗粒在共混物中的选择性定位，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通过内部混合器或溶液铸造方法在熔融状态下制备，以改善纳米颗粒的分散。可能会使用相容剂来降低聚合物组分之间的界面张力并改善纳米颗粒的分散。剪切和拉伸流动中的流变学将用于验证共混物和纳米复合材料形态的稳定性，并评估使用或不使用增塑剂的纳米颗粒在控制液滴聚结方面的效率。将测定共混纳米复合材料的基本热力学、拉伸和冲击性能，并与聚丙烯进行比较。最后，对于选定的纳米复合材料，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 their final properties. Potential nanoparticles are cellulose nanocrystals (CNCs), nanoclay (montmorillonite, sepiolite, halloysite nanotubes), carbon nanotubes and graphene. The Hansen solubility parameter differences between various two components of the potential nanocomposites and polymer components will be determined and correlated with the apparent yield stress determined from rheology. These results will be used to make selections of components of most promising nanocomposites. Selective localization of the nanoparticles in the blends will be sought, in particular at the interface of both polymer components. These blends and nanocomposites will be prepared in the molten state via an internal mixer or in solution-cast methods to improve the dispersion of the nanoparticles. Possibly a compatibilizer will be used to reduce the interfacial tension between the polymer components and improve the dispersion of the nanoparticles. Rheometry in shear and elongational flows will be used to verify the stability of the blend and nanocomposite morphology and assess the efficiency of the nanoparticles with or without plasticizers in controlling droplet coalescence. Basic thermo-mechanical, tensile and impact properties of the blend nanocomposites will be determined and compared to those of polypropylene. Eventually, for selected nanocomposites, electrical or barrier properties as well as foamability would be evaluated. Fundamental and original knowledge will be gained on the use of nanoparticles and the effect of their nature and geometry on the control and stabilization of the morphology of blends. The major impact of this work will be to provide key formulations for novel PLA blend nanocomposites with outstanding properties for applications in the automotive and electronic sectors as well as in biomedical fields, sectors of major importance for Canada.