SiC填充PP/FA复合材料拉伸强度及分形特征

目的定量研究不同含量碳化硅晶须(SiC)对聚丙烯(PP)/粉煤灰(FA)复合材料拉伸强度以及拉伸断口复杂程度的影响。方法以聚丙烯为基体,马来酸酐接枝聚丙烯(PP-g-MAH)为相容剂,FA和SiC为填料,采用熔融共混法制备PP/FA/SiC复合材料。利用电子万能试验机测试复合材料的拉伸强度,同时采用扫描电镜对拉伸断口进行形貌分析,并基于分形原理,利用差分盒维计数法计算复合材料拉伸断面的分形维数,分析研究复合材料拉伸断面的分形维数与其拉伸强度间的关系。结果复合材料的拉伸断面分形维数在1.24~1.90之间,相关系数均大于0.9,说明其具有统计意义上的自相似和较强的相关性。结论复合材料拉伸强度的对数与其断面的分形维数呈线性函数关系。

Tensile Strength and Fractal Characteristics of SiC Filled PP/FA Composites

The work aims to quantitatively study the effect of different contents of SiC whisker (SiC) on the tensile strength and tensile fracture complexity of polypropylene (PP)/fly ash (FA) composites. Firstly, PP/FA/SiC composites were prepared by melt blending method with PP as the matrix, maleic anhydride graft polypropylene (PP-g-MAH) as the compatibilizer, and FA and SiC as the filler. Secondly, the tensile strength of the composites was tested by the electronic universal tester; meanwhile, the tensile fracture pattern was analyzed by SEM. Then, based on the fractal principle, the fractal dimension of the composite''s tensile fracture was calculated by the difference box dimension counting method, and the relationship between the fractal dimension of the tensile fracture and the tensile strength of the composites was analyzed and studied. As a result, the fractal dimension of tensile fracture of the composites was between 1.24 and 1.90, and the correlation coefficient was more than 0.9, which indicated that it had statistically significant self-similarity and strong correlation. In conclusion, the logarithm of the tensile strength of the composites is in a linear functional relationship with the fractal dimension of the fracture.