Gao Honghong, Qiang Tao
School of Mechatronic Engineering, Xi'an Technological University, Xi'an 710021, China.
School of Materials Science & Chemical Engineering, Xi'an Technological University, Xi'an 710021, China.
Materials (Basel). 2017 Jun 7;10(6):624. doi: 10.3390/ma10060624.
Polylactide (PLA)-based composite materials reinforced with ball-milled celluloses were manufactured by extrusion blending followed by injection molding. Their surface morphology from impact fracture were imaged with scanning electron microscopy (SEM) and investigated by calculating their fractal dimensions. Then, linear regression was used to explore the relationship between fractal dimension and impact strength of the resultant cellulose/PLA composite materials. The results show that filling the ball-milled celluloses into PLA can improve the impact toughness of PLA by a minimum of 38%. It was demonstrated that the fracture pattern of the cellulose/PLA composite materials is different from that of pristine PLA. For the resultant composite materials, the fractal dimension of the impact fractured surfaces increased with increasing filling content and decreasing particle size of the ball-milled cellulose particles. There were highly positive correlations between fractal dimension of the fractured surfaces and impact strength of the cellulose/PLA composites. However, the linearity between fractal dimension and impact strength were different for the different methods, due to their different R-squared values. The approach presented in this work will help to understand the structure-property relationships of composite materials from a new perspective.
通过挤出共混然后注塑成型制备了用球磨纤维素增强的聚乳酸（PLA）基复合材料。用扫描电子显微镜（SEM）对其冲击断裂后的表面形态进行成像，并通过计算分形维数进行研究。然后，采用线性回归方法探讨所得纤维素/PLA复合材料的分形维数与冲击强度之间的关系。结果表明，将球磨纤维素填充到PLA中可使PLA的冲击韧性至少提高38%。结果表明，纤维素/PLA复合材料的断裂模式与原始PLA不同。对于所得复合材料，冲击断裂表面的分形维数随球磨纤维素颗粒填充量的增加和粒径的减小而增大。断裂表面的分形维数与纤维素/PLA复合材料的冲击强度之间存在高度正相关。然而，由于不同方法的决定系数（R平方值）不同，分形维数与冲击强度之间的线性关系也不同。本工作提出的方法将有助于从新的角度理解复合材料的结构-性能关系。
