HDPE及增韧HDPE的力学性能与测试条件的关系

于23℃时,研究了拉伸、弯曲速度及试样缺口剩余宽度对高密度聚乙烯(HDPE)、HDPE/弹性体、HDPE/E型增韧母料(E-TMB)的拉伸、弯曲及冲击强度等力学性能的影响。结果表明,所研究的测试条件对这三种材料力学性能影响的程度不同:对于这三种材料,均是拉伸速度对拉伸屈服应力、弹性模量影响的程度较小,对断裂伸长率影响的程度较大,弯曲速度对弯曲弹性模量、弯曲强度影响的程度较大;三种材料中,拉伸速度对断裂伸长率影响程度最大的是HDPE/弹性体,最小的是HDPE/E-TMB,弯曲速度对弯曲弹性模量、弯曲强度影响程度最大的是HDPE/E-TMB,最小的是HDPE/弹性体;随外力作用速度增大性能并非匀速变化,对不同的材料、不同的性能有相应的敏感区;试样缺口剩余宽度对HDPE/E-TMB的悬臂梁缺口冲击强度影响程度较大,而且缺口剩余宽度由7.8mm增加到8.0mm是影响的敏感区,对HDPE、HDPE/弹性体的影响的程度很小。

Relationship of Mechanical Properties of HDPE and Toughened HDPE with Test Conditions

The effecs of the tensile rate, bending speed and notched residual breadth of the sample on the mechanical properties, such as tensile, bending and impact strength, of HDPE, HDPE/elastomer and HDPE/E-TMB at 23 % were studied. The results indicated the effects of the studied test conditions on the mechanical properties of the materials were different, in which the effec of the tensile rate on tensile yield stress and elastic modulus was smaller, but that on elongation at break was great, the effect of bending speed on bending modulus and bending strength was great; the effect of tensile rate on elongation at break was the greatest for HDPE/elastomer, and the smallest for HDPE/E-TMB, the effect of bending speed on for HDPE/E-TMB, and the smallest for HDPE/elastomer; augmentation of external force speed, different materials and bending modulus and bending strength was the greatest the change of the properties was not uniform with the different properties had respective sensitive section; the effect of notched residual breadth of sample on notched Izod impact strength of HDPE/E-TMB was great; the notched residual breadth from 7.8mm to 8.0mm was a sensitive section, the effect of notched residual breadth of sample on notched Izod impact strength of HDPE and HDPE/elastomer was small.