常见车用环境对聚己内酰胺材料性能的影响

Effects of Common Vehicle Environments on Mechanical Properties of Polycaprolactam

为分析应用于汽车的聚己内酰胺(PA6)材料在实际使用工况下,环境对其性能的影响,研究了不同车用环境对PA6材料的拉伸、弯曲、压缩、冲击等力学性能的影响,并且,对其拉伸断面形貌进行了分析。结果表明,不同环境对PA6材料性能变化的影响明显不同。当PA6在-40℃低温条件下放置24 h,或在95号汽油中浸泡720 h时,PA6材料的力学性能大部分保持率可在90%~110%,断面形貌基本无变化。当在温度为80℃条件下放置500 h,或120℃条件下放置24 h时,PA6材料的强度增大,性能变化率范围为15.3%~63.8%,韧性降低,性能变化率在-8.1%~-85.9%之间,拉伸断面应力发白情况减少。在玻璃水和洗车液中浸泡时,随着浸泡时间的增大,材料的韧性逐渐增加、强度逐渐降低,拉伸断面基本无应力发白情况。

In order to verify the performance variation of polycaprolactam(PA6)used in vehicle under actual using conditions,we studied the effects of different automotive environments on the mechanical properties of PA6,such as tensile properties,bending properties,compression properties and impact properties.In addition,the tensile fracture morphology was also analyzed.The results showed that different environments had different influences on the properties of PA6.When PA6 was placed at-40℃for 24 h or immersion in 95#gasoline for 720 h,most of the mechanical properties could be maintained between 90%~110%,and the fracture morphology was almost unchanged.After placing PA6 at 80℃for 500 h or 120℃for 24 h,the material strength increased,and the performance change rate was between 15.3%~63.8%.The toughness and stress whitening observed on the tensile fracture decreased,the toughness performance change rate was between-8.1%~-85.9%.When the PA6 material was immersed in glass water and car shampoo,with the increase of immersion time,the toughness of the material gradually increased,the strength of the material gradually decreased,and the tensile fracture was generally free of stress whitening.