耐老化无卤阻燃TPU复合材料的制备与性能研究

Study on Preparation and Properties of Anti-aging and Halogen-Free Flame Retarded TPU Composites

将不同质量比的间苯二酚双[二(2,6-二甲基苯基)磷酸酯]/三聚氰胺氰尿酸盐(RDX/MCA)复配阻燃剂添加到热塑性聚氨酯弹性体(TPU)中,通过共混挤出制备了无卤阻燃TPU复合材料。采用极限氧指数(LOI)和垂直燃烧测试(UL 94)评估了复合材料的阻燃性能,利用万能拉力试验机测定了复合材料的力学性能,同时通过热氧老化、UV老化及水解老化实验考察了复合材料的耐老化性能。结果表明:当复配阻燃剂用量为15%、RDX与MCA的质量比为1:1时,TPU复合材料通过UL 94V-0级(1.6 mm)垂直燃烧测试,LOI达到28.1%,拉伸强度、断裂伸长率和撕裂强度分别为23.8 MPa、566%和95 kN/m。此外,复合材料分别经热氧老化、UV老化及水解老化168 h后,阻燃性能无明显变化,力学性能保持率均在75%以上,具有较好的耐老化性能。

The halogen-free flame retarded thermoplastic polyurethane(TPU)composites were prepared by adding compound flame retardant tetrakis(2,6-dimethylphenyl)1,3-phenylene bisphosphate/melamine cyanurate(RDX/MCA)with different mass ratio.The flame-retardant properties of the TPU composites were evaluated by limiting oxygen index(LOI)and vertical burning tests(UL 94),and the mechanical properties of the composites were measured by universal tensile machine.In addition,the aging-resistant properties of TPU composites were investigated by the tests of thermo-oxidative aging,UV aging and hydrolyzing aging.The results reveal that the flameretardant properties of TPU composites reaches to UL 94 V-0 rating(1.6 mm)and the LOI value is 28.1%,when the content of compound flame retardant is 15% and the mass ratio of RDX/MCA is 1/1.Meanwhile,the tensile strength,elongation at break and tear strength of the composite is 23.8 MPa,566% and 95 kN/m,respectively.Moreover,the TPU composites retain the flame-retardant properties and the retention rate of mechanical properties of the composites exceeds over 75% after thermo-oxidative aging or UV aging or hydrolyzing aging for 168 h.