Surface Modification of Intumescent Flame Retardant and Its Application in Polypropylene with Excellent Fire Performance and Water Resistance

作者：Xuqiang Zheng, Mike Deng, Hao Jia, Xinyu Chen, Ruicheng Wang, Jun Sun, Hongfei Li, Xiaoyu Gu, Sheng Zhang · 发表于：Polymers · 年份：2025 · DOI：10.3390/polym17030399 · 被引用次数：16 · 研究领域：Flame retardant materials and properties、Fire dynamics and safety research、Synthesis and properties of polymers

Polypropylene (PP) has a wide range of applications in daily life but it is highly flammable. Intumescent flame retardants (IFRs) are used to improve the flame-retardant performance of polypropylene. However, the poor compatibility between IFRs and PP poses significant challenges. In this study, an IFR was reacted with γ-aminopropyl triethoxysilane (KH550) to introduce necessary reactive sites on the surface of the IFR. Subsequently, maleic anhydride-grafted SBS (SBS-g-MAH) was reacted with KH550 to further coat the IFR, resulting in a modified IFR named MA-IFR. The effects of MA-IFR on the flame retardancy, mechanical properties, and water resistance of PP composites were systematically investigated. The limiting oxygen index of the PP/MA-IFR composite reached up to 39.7%, with the vertical burning test (UL-94) achieving a V-0 rating. Moreover, compared to the control PP, the peak heat release rate and peak smoke release rate were reduced by 85.0% and 82.5%, respectively. In addition, the mechanical properties of the PP composites were significantly improved, with tensile strength and impact strength increasing by 29% and 18%, respectively, compared to those of the PP/IFR composite. Notably, the PP/MA-IFR composite maintained excellent flame retardancy, even after being immersed in water at 70 °C for 168 h. These results demonstrate that MA-IFR offers a promising solution for producing flame-retardant and water-resistant PP composites.