Enhancing flame retardancy and ultraviolet aging resistance of intumescent flame retardant polypropylene by incorporating cerium oxide
Jingqi Feng, Ruiping Wang, Jiaqi Geng, Siqi Huo, Zhiyong Zhang, Miaojun Xu, Mingyang Zhu, Bin Li
Abstract
The flame-retardant modification of polypropylene (PP) often deteriorates its resistance to ultraviolet (UV) radiation, leading to severe degradation in both flame retardancy and mechanical properties during long-term service. To address this issue, cerium oxide (CeO₂) was incorporated into an intumescent flame retardant (IFR) system to achieve synergistic flame retardancy and enhance anti-UV performance. The resultant PP/IFR/CeO 2 achieved a UL-94 V-0 rating with a limiting oxygen index (LOI) of 32.7 % at a total loading of only 20 wt% IFR and CeO 2 . After UV irradiation for 120 h, the surface of PP/IFR/CeO 2 remained smooth, with only shallow cracks, and its water contact angle was maintained at 64.5°. The carbonyl index increased merely to 1.45, indicating a markedly low degree of photo-oxidative aging. In addition, the tensile strength and elongation at break decreased by 9.4 % and 28.5%, respectively, which were significantly smaller reductions than those of PP/IFR. The results indicate that CeO 2 can effectively improve the anti-UV performance and flame retardancy of PP/IFR, providing a valuable foundation for developing durable, flame-retardant PP composites with improved anti-UV performance.