Laboratory of Polymeric and Composite Materials, Center of Innovation and Research in Materials and Polymers (CIRMAP), University of Mons , Place du Parc 23, 7000 Mons (Belgium).
ACS Appl Mater Interfaces. 2012 Jul 25;4(7):3364-71. doi: 10.1021/am3008196. Epub 2012 Jul 16.
Cellulose nanowhiskers (CNW), extracted from ramie fibers by sulfuric acid hydrolysis, were used as substrates to compatibilize binary polyester blends containing 50/50 (w/w) polycaprolactone (PCL) and polylactide (PLA). To tailor their interfacial energy and fine-tune their adhesion with the components of the blend, CNW were subjected to different surface polyester grafting by the means of ring-opening polymerization. PCL and PLA homopolyesters as well as P(CL-b-LA) diblock copolymers were successfully grafted on the surface of CNW and the resulting substrates were loaded into the PCL/PLA blend by melt-blending. Morphological and rheological analyses were conducted in order to evaluate the ability of these nanoparticles to enhance the compatibility of PCL/PLA blends. Our results showed that unmodified CNW as well as (co)polyester-grafted CNW improved, at different levels, the compatibility of PCL/PLA blends by preventing from coalescence the dispersed domains. (co)polyester-grafted CNW also enhance the mechanical properties of the blend, which can be explained by the formation of cocontinuous phase morphology at the interface. Our findings suggest that (co)polyester-grafted CNW, especially CNW-g-P(CL-b-LA) diblock copolymers, can serve as a suitable nanofiller to tune the compatibility of PCL/PLA blends and their related microstructures.
纤维素纳米纤维（CNW）通过硫酸水解从苎麻纤维中提取出来，被用作二元聚酯共混物的增容剂，该共混物含有 50/50（w/w）的聚己内酯（PCL）和聚乳酸（PLA）。为了调整其界面能并微调与共混物成分的粘附性，CNW 通过开环聚合进行了不同的表面聚酯接枝。成功地在 CNW 表面接枝了 PCL 和 PLA 均聚物以及 P(CL-b-LA)嵌段共聚物，并用熔融共混法将得到的底物加入到 PCL/PLA 共混物中。进行了形态和流变分析，以评估这些纳米粒子增强 PCL/PLA 共混物相容性的能力。我们的结果表明，未改性的 CNW 以及（共）聚酯接枝的 CNW 通过阻止分散相的聚结，在不同程度上改善了 PCL/PLA 共混物的相容性。（共）聚酯接枝的 CNW 还增强了共混物的力学性能，这可以通过界面处形成共连续相形态来解释。我们的研究结果表明，（共）聚酯接枝的 CNW，特别是 CNW-g-P(CL-b-LA)嵌段共聚物，可以作为一种合适的纳米填料，来调节 PCL/PLA 共混物及其相关微观结构的相容性。
