基于环三磷腈/磷酸酯反应型磷-氮阻燃剂的合成、热降解及应用

以六氯环三磷腈(HCCP)、对羟基苯甲醛及亚磷酸二乙酯等为原料,成功合成了一种反应型磷-氮膨胀阻燃剂六(4-磷酸二乙酯羟甲基苯氧基)环三磷腈(HPHPCP),HPHPCP结构经傅里叶红外光谱(FTIR)、核磁共振(NMR)证实。热失重(TG/DTG)表明HPHPCP具有较高的热稳定性及良好的成炭性,氮气氛下的起始分解温度为162.7℃,800℃时残炭量大于40%(质量分数);利用HPHPCP的羟基结构,应用于硬质聚氨酯泡沫塑料中,可以显著提高聚氨酯硬泡的阻燃性能,添加30%的HPHPCP就可以使聚氨酯氧指数达到27%。

Synthesis,properties and application of reactive nitrogen-phosphorus flame retardant

A novel reactive flame retardant named hexakis (4-diethyl phosphate hydroxymethyl phenoxy) cyclotriphosphazene (HPHPCP) was synthesized from hexachlorocyclotriphosphazene (HCCP), p-hydroxy benzaldehyde and diethyl phosphite. Chemical structures of intermediate and HPHPCP were characterized by Fourier-transform infrared spectroscopy (FTIR), proton and 31P nuclear magnetic resonance (NMR). Thermal stability of the HPHPCP was determined via thermogravimetric analysis (TGA). Halogen-free flame-retardant rigid polyurethane foams (RPU) were prepared by using HPHPCP as a reactive flame retardant. The effect of HPHPCP content on the thermal and flame-retardant properties of RPU was investigated with TGA, and limiting oxygen index (LOI). The temperatures of 5%(mass) loss (T_5%) of HPHPCP in nitrogen and air were 162.7℃ and 153.0℃, and the residues at 800℃ of HPHPCP in nitrogen and air were 42.1% and 12.0%(mass), respectively. HPHPCP could enhance thermal stability of RPU. The T_5% of RPU-20%HPHPCP was 193.9℃, 20℃ higher than pure RPU. Moreover, limiting oxygen index (LOI) of RPU increased with increasing HPHPCP, and LOI of RPU-30%HPHPCP was 27%.