聚酰胺在中国典型环境中的老化规律及其机理探讨

在中国西部及东部4个地点进行了一年的老化曝晒实验，聚酰胺材料的力学性能出现了不同程度的下降，表面出现了不同程度的裂纹。通过室内不同湿度模拟实验和紫外加速老化实验的对比，研究了环境湿度、紫外线对材料力学性能及表面形貌的影响。结果表明：中国东部地区老化程度明显大于西部地区；环境湿度是影响聚酰胺老化过程中力学性能变化的重要环境因子，湿度越大，力学性能下降越多；紫外线是材料表面裂纹形成的决定因素，而高湿度能促进裂纹的形成，两者有一定的复合效应。

Behaviors and Mechanism of Polyamide Aging in Typical Environment

The aging behaviors of polyamide were studied by exposure experiments at the four spots in the west and east of China. The mechanical properties decreased with the exposure time. Simultaneity, the cracks were found on the surface pattern. And the degree was different among spots. The effect of moisture and ultraviolet radiation on the mechanical properties and the surface pattern of polyamide were studied. The results indicate that polyamide in west of China deteriorate faster than that in east of China, and the key factor that led to the change of the mechanical properties is the absorbed water and ultraviolet radiation is the main factor that results in cracks in the surfaces of polyamide samples. And the existence of water strengthens the influence of ultraviolet radiation. Therefore, it can be concluded that the ageing of polyamide is accelerated by the ultraviolet radiation and the environmental humidity.