酚醛树脂基新戊二醇磷酸酯阻燃剂的合成及其性能研究

通过用新戊二醇磷酰氯对线型酚醛树脂(PF)酚羟基实行磷酰化封端处理,制备了线型PF基新戊二醇磷酸酯(NDMPP)阻燃剂,将其应用于阻燃PA6。采用核磁共振氢谱(1H NMR)、核磁共振磷谱(31P NMR)和傅立叶变换红外光谱(FTIR)表征了NDMPP的结构,采用热重(TG)分析研究其热分解行为,采用极限氧指数(LOI)和UL 94测试其阻燃PA6材料的阻燃性能,采用万能材料试验机和冲击试验机测试阻燃材料的力学性能。1H NMR,31P NMR和FTIR结果表明,线型PF中大约82%的羟基被磷酰化,NDMPP中的磷含量约为11.9%。TG分析结果表明,NDMPP阻燃剂在氮气气氛下起始分解温度超过250℃,600℃的残炭率达到43.5%,显示出良好的热稳定性。当NDMPP质量分数为25%时,其阻燃的PA6达到UL 94 V–0等级,LOI达到33.4%,而拉伸强度、缺口冲击强度、弯曲强度和弯曲弹性模量分别为纯PA6的76%,41%,72%和71%。

Synthesis and Properties of Novolac-based Neopentyl Glycol Cyclic Phosphate Flame Retardant

A novolac-based neopentyl glycol cyclic phosphate (NDMPP)flame retardant was synthesized based on novolac resin terminated with neopentyl glycol chlorophosphate by phosphorylation and it was used forflame retardingpolyamide (PA) 6. The chemical structure of NDMPP was characterized by Fourier transform infrared spectroscopy (FTIR),1H and31P nuclear magnetic resonance (1H NMR and31P NMR). The thermal stability of NDMPP was studied by thermo gravimetric (TG) analysis. NDMPP flame retardant PA6 was evaluated by limiting oxygen index (LOI) and vertical burning test (UL 94),the mechanical properties of the flameretardant PA6 were tested by universal material testing machine and impact testing machine. The results of1H NMR,31P NMR and FTIR shows that about 82% of the novolac’s hydroxyl groups are successfully phosphorylated,and the phosphorus content of NDMPP achieves 11.9%. TG analysis results show that starting decomposition temperature of NMDPP increases to over 250℃ under nitrogen atmosphere,and char residue at 600℃ achieves to 43.5%,which reveal outstanding thermal stability. When the mass frac-tion of NDMPP is 25%,PA6flame-retardanted by NDMPP reaches UL 94 V–0 rating and LOI value is 33.4%,the tensile strength, notched impact strength,flexural strength andflexural modulus of theflame retardant PA6 is 76%,41%,72% and 71% of the corre-sponding value of pure PA6,respectively.