Abstract: The application of post-consumer recycling (PCR) materials in automotive bumpers and other key components is limited by its insufficient mechanical properties, poor paint adhesion, easy foaming and other problems. This paper studies the comparative study of the performance of different recycled polypropylene (PP), and screens out the recycled PP with excellent performance. It is applied to PP+(Ethylene-Propylene-Diene Monomer, EPDM)-TD20, and its mechanics, spray painting and boiling foaming properties are discussed. The results shows that the example properties of the recycled materials are slightly lower than that of the new materials. Differential scanning calorimetry (DSC) and infrared spectroscopy show that the main components of all samples are PP resin. The boiling foaming experiment show that new material PP1>recycled material PP2>recycled material PP3=recycled material PP4. In the PP+EPDM-TD20 system, compared to recycled material PP3, recycled material PP2 exhibits better mechanical properties and resistance to water foaming. This suggests that the surface interface binding force between the recycled material PP2 surface and the paint, as well as its adsorption capacity for small organic molecules in the paint, are stronger. Consequently, small molecule desorption does not occur under high-temperature boiling conditions, thereby avoiding defects such as blistering and wrinkling due to interface layer peeling. When the content of recycled material PP2 is 30% and the content of polyolefin elastomer (POE) is 20%, the mechanical properties and spray painting performance of the sample are optimal, and the sample passes both the 100-cell adhesion test and the boiling foaming test, meeting the performance requirements for bumper materials.

Key words: polypropylene; PCR material; spray-painted bumper; boiling foaming

摘要： 后消费者回收（PCR）材料在汽车保险杠等关键部件上的应用受限于其力学性能不足、 油漆附着力差、易起泡等问题，文章研究不同再生料聚丙烯（PP）性能的对比研究，筛选出 性能优良的再生料 PP，并应用于 PP+三元乙丙橡胶（EPDM）-TD20 规格材料中，探讨其力 学、喷漆及水煮起泡性能。结果表明，再生料的例学性能较新料略低，差示扫描量热仪（DSC） 和红外谱图显示，所有试样主要成分均为 PP 树脂。水煮起泡实验表明，新料 PP1>再生料 PP2> 再生料 PP3=再生料 PP4；在 PP+EPDM-TD20 规格体系内，相较于再生料 PP3，再生料 PP2 的力学、耐水煮起泡性能更优，表明再生料 PP2 表层与油漆之间的表面界面结合力和对油漆 中有机小分子的吸附能力较强，在高温水煮条件下不出现小分子脱附，避免因为界面层被剥 离出现起泡和起皱等缺陷。当再生料 PP2 含量为 30%，聚烯烃弹性体（POE）含量为 20%时， 试样的力学性能和喷漆性能最优，百格附着力测试和水煮起泡测试均合格，满足保险杠材料 性能要求。

关键词: 聚丙烯；PCR 材料；喷漆保险杠；水煮起泡