Sodium fumarate (SF, C₄H₃NaO₄), as a low-cost and environment-friendly additive, has been applied as the fire safety agent to investigate the flame retardancy and smoke suppression property in thermoplastic polyurethane elastomer (TPU). A series of tests were carried out, including limiting oxygen index (LOI), cone calorimeter test (CCT), smoke density test (SDT), and thermogravimetric/Fourier transform infrared spectroscopy (TG-IR). The results proved that the addition of SF can significantly improve the fire safety property of TPU. Remarkably, in the case of the sample containing 2.0 wt% SF, LOI was raised up to 27.5 compared with 21.0 of pure TPU. The CCT results showed that pHRR, THR, TSR, and SF values decreased by 60.1%, 17.0%, 44.6%, and 66.4%, respectively, while the residual mass increased from 3.0% to 12.3% compared with pure TPU. The digital photographs displayed a more compact and intense carbon layer after the addition of SF. The SDT results indicated SF has increased the luminous flux and reduced Ds values, implying the improvement of the smoke suppression property of TPU. TG and TG-IR results showed that the addition of SF has promoted the char forming process and reduced the release of CO₂ and other volatile compounds. All results of tests illustrated that SF has considerable fire safety effect on TPU. Through the analysis of the results of this experiment, it will make a significance in the aspect of fire safety of polymer.

中文翻译：

---

富马酸钠基热塑性聚氨酯弹性体防火效果研究

富马酸钠（SF、C ₄ H ₃ NaO ₄)，作为一种低成本、环保的添加剂，已被用作防火剂，以研究热塑性聚氨酯弹性体 (TPU) 的阻燃和抑烟性能。进行了一系列测试，包括极限氧指数（LOI）、锥形量热仪测试（CCT）、烟雾密度测试（SDT）和热重/傅里叶变换红外光谱（TG-IR）。结果证明，SF的加入可以显着提高TPU的防火性能。值得注意的是，在含有 2.0 wt% SF 的样品的情况下，LOI 提高到 27.5，而纯 TPU 为 21.0。CCT结果显示，与纯TPU相比，pHRR、THR、TSR和SF值分别降低了60.1%、17.0%、44.6%和66.4%，而残留质量从3.0%增加到12.3%。添加SF后，数码照片显示出更致密和强度更高的碳层。SDT结果表明SF增加了光通量并降低了Ds值，这意味着TPU的抑烟性能得到了改善。TG和TG-IR结果表明SF的加入促进了成炭过程并减少了CO的释放₂和其他挥发性化合物。所有的测试结果都表明SF对TPU具有相当大的防火效果。通过对本实验结果的分析，将对聚合物防火安全方面具有重要意义。