次磷酸铝/三聚氰胺氰尿酸盐阻燃热塑性聚氨酯的性能研究

Study on Properties of Flame Retardant TPU with AHP/MCA Composites

将次磷酸铝(AHP)和三聚氰胺氰尿酸盐(MCA)复配后添加到热塑性聚氨酯(TPU)中制备阻燃TPU材料,通过氧指数(OI)和垂直燃烧(UL 94)测试研究了材料的阻燃性能,通过热重分析(TGA)技术测定了材料的热稳定性及成炭性能,同时还研究了AHP与MCA不同的质量比对TPU材料性能的影响。结果表明:当AHP与MCA的质量比为1:2,阻燃剂的总添加量为11%时,阻燃TPU材料能通过垂直燃烧UL 94V-0级,OI达到了25.2%。TGA测试结果表明:阻燃剂AHP/MCA的加入对TPU材料的起始热分解温度没有影响,但能提高材料在高温时的热稳定性,同时提高材料的成炭性能。增加的炭层能有效地阻止氧气和热量进入到材料内部,抑制内部可燃性气体的逸出,同时AHP与MCA能释放出难燃气体,稀释氧气及可燃性气体的浓度,从而提高了材料的阻燃性能。

Aluminum hypophosphite（AHP） combined with melamine cyanurate（MCA） was incorporated into thermoplastic polyurethane（TPU） to prepare flame retardant TPU materials. The flame retardant properties of materials were investigated by limiting oxygen index（OI） and vertical burning（UL 94） tests, and the thermal stability and charring capacity of TPU composites were evaluated by thermogravimetric analysis（TGA）. Meanwhile, the effect of mass ratio between AHP and MCA on the flame retardancy of TPU was also investigated. The results reveal that the flame retardant TPU composites reaches to UL 94V-0 rating and OI value is 25.2% when the total loading amount of flame retardant is only 11% with the mass fraction of AHP/MCA is 1/2. The TGA tests demonstrated that the initial decomposition temperature of materials change hardly the incorporation of AHP/MCA complex, but the thermal stability of flame retardant TPU at high temperature enhances and the materials charring forming promotes. The increased char residue can effectively prevent oxygen and heat from entering into the underlying matrix, and suppress the volatilization of combustible gas. At the same time, the incombustible gas releases from the decomposition of AHP and MCA can dilute the concentration of oxygen and combustible gases in combustible zone, consequently improves the flame retardancy of TPU materials.