Jiang Lijuan, Zhou Yinzhi, Jin Fengnian, Hou Zhenhua
International Institute for Urban Systems Engineering, Southeast University, Nanjing 210096, China.
College of National Defense Engineering, Army Engineering University of PLA, Nanjing 210007, China.
Polymers (Basel). 2023 Jan 12;15(2):408. doi: 10.3390/polym15020408.
To investigate the influence of polymer matrices on the tensile and impact properties of long fiber-reinforced thermoplastic (LFT) composites, composites of long basalt fiber-reinforced thermoplastic were developed in this work. Two types of polyethylene, namely 8008 and 100S, and two types of polyethylene, namely C4220 and K8303, were chosen as the matrices. The fiber volume fractions were set as 2.8%, 5.9%, 8.1%, and 10.6%. The melt flow index (MFI), crystallinity, tensile properties, impact strength, and fracture morphology of the neat polymers and the corresponding composites were tested. The composites of 8008 showed the highest tensile strength since neat 8008 showed a much higher MFI value and crystallinity. The composites of 8008 and K8303 showed a much higher tensile modulus since the neat thermoplastic showed a higher tensile modulus than the other two composites. The polymer toughness was the factor that determined whether the polymer could be toughened by fibers. Moreover, the interfacial shear strength was calculated and compared with the matrix shear strength, based on which fracture modes of the LFT were predicted. Effective methods were proposed for further improvement of the mechanical properties. The results of this paper were essential for attaining the anticipated properties when designing LFT composites.
为了研究聚合物基体对长纤维增强热塑性塑料（LFT）复合材料拉伸性能和冲击性能的影响，本文制备了长玄武岩纤维增强热塑性塑料复合材料。选用了两种聚乙烯，即8008和100S，以及两种聚丙烯，即C4220和K8303作为基体。纤维体积分数设定为2.8%、5.9%、8.1%和10.6%。测试了纯聚合物及其相应复合材料的熔体流动指数（MFI）、结晶度、拉伸性能、冲击强度和断裂形态。8008复合材料的拉伸强度最高，因为纯8008具有更高的MFI值和结晶度。8008和K8303复合材料的拉伸模量更高，因为纯热塑性塑料的拉伸模量高于其他两种复合材料。聚合物韧性是决定聚合物是否能被纤维增韧的因素。此外，计算了界面剪切强度并与基体剪切强度进行比较，据此预测了LFT的断裂模式。提出了进一步改善力学性能的有效方法。本文的结果对于设计LFT复合材料时获得预期性能至关重要。
