Research on the fire safety effect of thermoplastic polyurethane elastomer based on sodium fumarate

Abstract Sodium fumarate (SF, C 4 H 3 NaO 4 ), 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 CO 2 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.