玄武岩纤维增强聚乳酸力学性能及耐老化性能

通过拉伸实验和老化实验,研究了玄武岩纤维含量对BF/PLA拉伸性能、抗冲击性能及耐老化性能的影响规律,通过DSC实验得到BF/PLA复合材料的结晶度,分析其耐老化原因。随着质量分数增加,其拉伸强度增加可达到141 MPa,弹性模量达到5 GPa,达到峰值后又减小。质量分数达到30%时,缺口冲击强度和非缺口冲击强度分别达到6.7 kJ/m²和20.76 kJ/m²。DSC实验结果表明,随着玄武岩纤维含量的增加,聚乳酸复合材料的结晶度由34.6%增加到54.6%,而结晶度的增加可以减缓聚乳酸的降解速度。当质量分数达到60%时,老化实验后的弹性模量可以保持降解前的77%,延缓降解速度较为明显。经分析,拉伸强度与玄武岩纤维质量分数呈二次多项式关系,而弹性模量与玄武岩纤维质量分数之间呈线性关系。这种函数关系不受材料力学性能下降的影响。

Mechanical properties of basalt fiber-reinforced polylactide matrix and aging resistance properties

With tests, the tensile properties, impact properties and aging resistance of PLA composites with basalt fibers as reinforcement were investigated. With DSC, crystallininty of the basalt fiber composites are obtained. With the mass fraction increasing, tensile strength and tensile modulus reach 141 MPa and 5 GPa respectively which are the best. However, the tensile properties decrease. The impact strength reach 20.76 kJ/m² and 6.7 kJ/m² respectively when the mass fraction is 30%. The results of DSC test show that the crystallinity of polylactic acid composite increases from 34.6% to 54.6% with the increase of basalt fiber content, and the increase of crystallinity can slow down the degradation rate of polylactic acid. After 48 h accelerated aging, the tensile modulus maintains 77% of the value before the aging test. Stable functional relationships that are not affected by aging between the tensile properties and mass fraction are found. Second linear fitting relationship is found between tensile strength and mass fraction. Near linearity is found between the tensile modulus and mass fraction.