Wang Hui, Wang Shuang, Du Xiaosheng, Wang Haibo, Cheng Xu, Du Zongliang
Textile Institute, College of Light Industry, Textile and Food Engineering, Sichuan University Chengdu 610065 China
RSC Adv. 2019 Mar 11;9(13):7411-7419. doi: 10.1039/c8ra09838g. eCollection 2019 Mar 1.
An intumescent flame retardant (DOPO-DAM) containing phosphorus and nitrogen was synthesized a two-step process and then, it was incorporated into waterborne polyurethane to serve as a reactive flame retardant for preparing flame-retarded WPU (FR-WPU). The chemical structures of DOPO-DAM and FR-WPU were confirmed by H NMR, P NMR, and FTIR studies. The thermal stability, flame retardancy and mechanical properties of FR-WPU were investigated by TGA, TGA-FIR, Py-GC-MS, limiting oxygen index (LOI) test, SEM-EDS analysis, cone calorimeter test and a universal testing machine. The results showed that the conjugation of DOPO-DAM into WPU induced a slight decline in the thermal stability of FR-WPU. However, the incorporation of DOPO-DAM into WPU significantly enhanced the flame retardancy by reducing the heat release rate (HRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP). In addition, the morphology, elemental composition and content of the residual char of the flame-retarded WPU indicated the important function of DOPO-DAM in the condensed phase. Thus, DOPO-DAM exhibited gas-phase and condensed-phase flame retardant effects on the WPU films.
通过两步法合成了一种含磷和氮的膨胀型阻燃剂（DOPO-DAM），然后将其引入水性聚氨酯中，作为反应型阻燃剂制备阻燃水性聚氨酯（FR-WPU）。通过¹H NMR、³¹P NMR和FTIR研究确定了DOPO-DAM和FR-WPU的化学结构。通过TGA、TGA-FIR、Py-GC-MS、极限氧指数（LOI）测试、SEM-EDS分析、锥形量热仪测试和万能试验机对FR-WPU的热稳定性、阻燃性和力学性能进行了研究。结果表明，DOPO-DAM与WPU共轭导致FR-WPU的热稳定性略有下降。然而，将DOPO-DAM引入WPU中，通过降低热释放速率（HRR）、总热释放（THR）、产烟速率（SPR）和总产烟量（TSP），显著提高了阻燃性。此外，阻燃水性聚氨酯残余炭的形态、元素组成和含量表明DOPO-DAM在凝聚相中的重要作用。因此，DOPO-DAM对WPU薄膜表现出气-固两相阻燃效果。
