INTECIN (UBA-CONICET), Engineering Faculty, University of Buenos Aires, Av. Las Heras 2214, C1127AAR Buenos Aires, Argentina.
Carbohydr Polym. 2013 Sep 12;97(2):269-76. doi: 10.1016/j.carbpol.2013.04.099. Epub 2013 May 9.
In the present work, composites based on a commercial starch/PCL blend (MaterBi-Z) reinforced with three different nanoclays: natural montmorillonite (Cloisite Na(+) (MMT)) and two modified montmorillonites (Cloisite 30B (C30B) and Cloisite 10A (C10A)) were prepared in an intensive mixer. The aim of this investigation was to determine the effect of the different nanoclays on the quasi-static fracture behavior of MaterBi-Z nanocomposites. An improvement in the fracture behavior for the composite with low contents of C30B was obtained, probably due to the easy debonding of clay achieved from a relatively weak filler-matrix interaction. On the other hand, a strong interaction had a detrimental effect on the material fracture toughness for the MaterBi-Z/C10A composites as a result of the higher compatibility of this organo-modified clay with the hydrophobic matrix. Intermediate values of fracture toughness, determined using the J-integral approach (Jc), were found for the composites with MMT due to its intermediate interaction with the matrix. The different filler-matrix interactions observed were also confirmed from the application of Pukánszky and Maurer model. In addition, multifractal analysis was applied to describe the topography of fracture surfaces. Thus, the complex fracture process could be successfully described by both experimental and theoretical tools. The obtained results suggest that it is possible to tailor the mechanical properties of the studied composites taking into account their further application.
在本工作中，以商业淀粉/聚己内酯共混物（MaterBi-Z）为基础，制备了三种不同纳米粘土增强的复合材料：天然蒙脱石（Cloisite Na(+) (MMT)）和两种改性蒙脱石（Cloisite 30B (C30B) 和 Cloisite 10A (C10A)）。本研究的目的是确定不同纳米粘土对 MaterBi-Z 纳米复合材料准静态断裂行为的影响。用低含量 C30B 的复合材料得到了断裂行为的改善，这可能是由于较弱的填料-基体相互作用导致粘土易于脱粘。另一方面，对于 MaterBi-Z/C10A 复合材料，由于这种有机改性粘土与疏水性基体的相容性较高，因此较强的相互作用对材料断裂韧性产生了不利影响。由于与基体的中等相互作用，用 MMT 制备的复合材料的断裂韧性值（Jc）为中间值，用 J 积分法确定。从 Pukánszky 和 Maurer 模型的应用也证实了不同的填料-基体相互作用。此外，多重分形分析被应用于描述断裂表面的形貌。因此，通过实验和理论工具成功地描述了复杂的断裂过程。得到的结果表明，可以考虑到它们的进一步应用，对研究复合材料的力学性能进行定制。
