Abstract: PP+EPDM-TD20 and thermoplastic vulcanizate (TPV) are widely used in the manufacturing of automotive exterior trims, and the performance degradation of polymer materials is more severe in moist and hot climate. Changing trends of the appearance and mechanical properties of PP+EPDM-TD20 and TPV are studied under xenon lamp test simulating moist and hot climate in this paper. The experimental results indicate that the gray scale, color difference and hardness of the two polymer materials basically remains unchanged, the gloss retention rate, tensile strength retention rate and breaking elongation show an approximate exponential downward trend, the flexural modulus of PP+EPDM-TD20 show an approximate exponential upward trend, while TPV shows an approximate exponential downward trend under 1 600 h xenon lamp irradiation. The fitted aging equation can provide important reference value for subsequent quantitative research on the performance degradation of automotive exterior trims.

Key words: PP+EPDM-TD20; TPV; Moist and hot climate; Xenon lamp test; Aging performance

摘要： PP+EPDM-TD20 和热塑性硫化橡胶（TPV）广泛应用于汽车外饰件的制造，高分子材 料的性能退化在湿润炎热气候下更加严重。文章通过对 PP+EPDM-TD20 和 TPV 进行模拟湿 润炎热气候下的氙灯试验，研究了这两种高分子材料外观及力学性能的变化趋势。实验结果 表明，两种材料在 1 600 h 氙灯照射下，灰度、色差、硬度基本保持不变，光泽度保持率、拉 伸强度保持率以及断裂伸长率呈近似指数下降趋势，PP+EPDM-TD20 的弯曲模量呈近似指数 上升趋势，而 TPV 呈近似指数下降趋势，拟合出的老化方程可为后续定量研究汽车外饰件的 性能退化提供重要的参考价值。

关键词: PP+EPDM-TD20；TPV；湿润炎热气候；氙灯试验；老化性能