磷腈衍生物大分子阻燃剂的合成及在聚丙烯中的应用

Synthesis of Macromolecule Phosphazene Derivative Flame Retardant and Its Application on Polypropylene

以六氯环三磷腈与1-氧基磷杂-4-羟甲基-2,6,7-三氧杂双环[2,2,2]辛烷(PEPA)为原料,合成出一种磷腈衍生物阻燃剂六(1-氧代-1-磷杂-2,6,7-三氧杂双环[2,2,2]辛烷-4-亚甲基)环三磷腈(PEPAP)。通过红外光谱和核磁共振氢谱表征了PEPAP的化学结构。熔融共混法构建PEPAP/聚丙烯(PP)阻燃体系并考察其热稳定性和阻燃性能。热重分析表明,PEPAP在N2中初始热分解温度为312℃,800℃时残炭率为34%。阻燃性能测试表明,当PEPAP质量分数为25%时体系的氧指数达29.4%,且体系能够通过UL94 V-0级。红外光谱和扫描电镜结果显示体系残炭炭层完整致密且含有磷酸酯类结构,表明PEPAP是固相阻燃机理。

A phosphorous-nitrogen containing intumescent flame retardant, named six （1-oxo-2, 6, 7-trioxa-1- phosphabicyclo [ 2, 2, 2 ] octane-4-methyl） eyclotriphosphazene （ PEPAP ） was synthesized by introducing caged phosphate to cyclotriphosphazene backbone. FT-IR and 1H-NMR were used to confirm the chemical structure of PEPAP. Flame retarded PEPAP/PP composites were prepared by melt blending. Thermal stability and flammability properties of PEPAP/PP composites were investigated by TGA, limited oxygen index （LOI） and UL 94 test. The results show that the addition of PEPAP enhances the thermal stability and flame retardaney of PP significantly. TGA results show that, in N2, Toner is 312℃ and the residue of PEPAP at 800℃ is 34 %. Also, the addition of PEPAP can dramatically improve the LOI value and UL 94 rating. For the 25 % PEPAP/PP sample, the LOI value is increased to 29.4 % and it can pass UL 94 V-0. The investigation of FT-IR and SEM for the residue reveals that the residual chars contain polyphosphoric or phosphoric acid. The intumescent chars formed from PEPAP and PEPAP/PP composites are intact, multicellular and strong, indicating a condensed flame retardant mechanism of PEPAP.