Center for Nanofibers and Nanotechnology, Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Singapore 117576, Singapore.
Department of Polymer Engineering, Faculty of Engineering, Golestan University, P.O. Box 491888369, Gorgan 1575949138, Iran.
Molecules. 2020 Nov 5;25(21):5157. doi: 10.3390/molecules25215157.
Polyethylene (PE) is one the most used plastics worldwide for a wide range of applications due to its good mechanical and chemical resistance, low density, cost efficiency, ease of processability, non-reactivity, low toxicity, good electric insulation, and good functionality. However, its high flammability and rapid flame spread pose dangers for certain applications. Therefore, different flame-retardant (FR) additives are incorporated into PE to increase its flame retardancy. In this review article, research papers from the past 10 years on the flame retardancy of PE systems are comprehensively reviewed and classified based on the additive sources. The FR additives are classified in well-known FR families, including phosphorous, melamine, nitrogen, inorganic hydroxides, boron, and silicon. The mechanism of fire retardance in each family is pinpointed. In addition to the efficiency of each FR in increasing the flame retardancy, its impact on the mechanical properties of the PE system is also discussed. Most of the FRs can decrease the heat release rate (HRR) of the PE products and simultaneously maintains the mechanical properties in appropriate ratios. Based on the literature, inorganic hydroxide seems to be used more in PE systems compared to other families. Finally, the role of nanotechnology for more efficient FR-PE systems is discussed and recommendations are given on implementing strategies that could help incorporate flame retardancy in the circular economy model.
聚乙烯（PE）是世界上应用最广泛的塑料之一，因其具有良好的机械和化学稳定性、低密度、成本效益高、易于加工、不易反应、低毒性、良好的电绝缘性和良好的功能。然而，其高可燃性和快速火焰传播对某些应用构成了危险。因此，不同的阻燃（FR）添加剂被掺入 PE 中以提高其阻燃性。在这篇综述文章中，全面回顾了过去 10 年关于 PE 系统阻燃性的研究论文，并根据添加剂来源进行了分类。阻燃剂根据其所属的阻燃剂家族进行分类，包括磷、三聚氰胺、氮、无机氢氧化物、硼和硅。指出了每个家族的阻燃机理。除了每种 FR 提高阻燃性的效率外，还讨论了其对 PE 系统力学性能的影响。大多数 FR 可以降低 PE 制品的热释放率（HRR），同时在适当的比例下保持力学性能。根据文献，与其他家族相比，无机氢氧化物似乎在 PE 系统中使用得更多。最后，讨论了纳米技术在更高效的 FR-PE 系统中的作用，并就实施有助于将阻燃性纳入循环经济模式的策略提出了建议。
