Abstract The effects of soft, polymeric interlayers on a brittle, mineral reinforced polymer matrix are investigated. Interlayers made of a standard polypropylene (PP) and a soft type of PP are introduced into matrix materials of either highly or moderately mineral particle reinforced PP. Single edge notch bending experiments are performed to characterize the fracture toughness of these composites. The experimental J-integral Jexp is used to describe the fracture toughness of the investigated materials. The multi-layered materials are compared to the homogeneous matrix material. A modified plotting technique is applied to more distinctly demonstrate the effects of soft layers on Jexp as a function of the crack extension Δa. The fracture toughness is evaluated and the slope of the J-Δa curves is used as a qualitative measure of crack growth resistance. In addition, the crack growth rate is recorded. The results show improvements in fracture toughness of almost twenty times of the matrix material, provided the material combination is chosen properly. This increase in fracture toughness is achieved due to a crack-arresting effect in the soft layers, which is followed by an energy-expensive crack re-initiation step.

中文翻译：

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通过矿物增强聚丙烯中的软夹层提高仿生韧性

摘要 研究了软聚合物夹层对脆性矿物增强聚合物基体的影响。由标准聚丙烯 (PP) 和软质 PP 制成的夹层被引入到高度或中等矿物颗粒增强 PP 的基体材料中。进行单边缺口弯曲实验来表征这些复合材料的断裂韧性。实验 J 积分 Jexp 用于描述所研究材料的断裂韧性。将多层材料与均质基质材料进行比较。应用修改后的绘图技术以更清晰地展示软层对 Jexp 的影响作为裂纹扩展 Δa 的函数。评估断裂韧性，并使用 J-Δa 曲线的斜率作为抗裂纹扩展性的定性量度。此外，还记录裂纹扩展速率。结果表明，如果材料组合选择正确，则断裂韧性几乎是基体材料的 20 倍。这种断裂韧性的增加是由于软层中的裂纹抑制作用实现的，随后是能量昂贵的裂纹重新引发步骤。