腰果酚基阻燃剂制备及对环氧树脂的阻燃抑烟效果

Preparation of cardanol-based flame retardant and its flame retardant and smoke suppression effect on epoxy resin

为有效改善环氧树脂(EP)的阻燃性能,首先以腰果酚、三聚氰氯、3-氯过氧苯甲酸、9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物为原料通过脱氯化氢、环氧化、开环加成反应制得了含磷杂菲结构的改性腰果酚基阻燃剂。使用傅里叶变换红外光谱对合成的阻燃剂表征,确定其化学结构。随后,加入一定量的4,4'-二氨基二苯基甲烷对EP进行固化。采用热重分析仪、锥形量热测试仪、极限氧指数(LOI)、水平垂直燃烧、扫描电子显微镜(SEM)等手段测试了EP的阻燃性能。结果表明,当加入质量分数为5%的阻燃剂时,EP在800°C热重测试中的残炭率从2.2%提升至19.8%。其LOI值从无添加时的23.7%提升到32.8%。锥形量热仪测得燃烧过程中的热释放率峰值、总热释放量、烟雾释放率和总烟雾释放量分别下降了34.9%,25.1%,22.2%,32.3%。水平垂直燃烧试验证明加入阻燃剂后,EP的阻燃等级从无等级提升至V-0级。利用SEM对燃烧后的残炭表层分析后发现,阻燃剂的加入会使EP在燃烧过程中表面形成一层致密的炭层以阻止燃烧。以上测试充分说明合成的腰果酚基阻燃剂对EP有着优异的阻燃和抑烟效果。同时在电子万能试验机上的力学性能测试表明,阻燃剂的加入对EP力学性能影响较小,不影响其在多领域的使用。

In order to effectively improve the flame-retardant properties of epoxy resin(EP),a modified cardanol-based flame retardant containing phosphophenanthrene was prepared by dehydrochlorination,epoxidation and ring-opening addition reaction with cardanol,cyanuric chloride,3-chloroperoxybenzoic acid and 9,10-dihydro-9-oxa-10-phosphenanthrin-10-oxide as raw materials.Fourier transform infrared spectroscopy was used to characterize the chemical structures of the synthesized flame retardants.Subsequently,a certain amount of 4,4'diaminodiphenylmethane was added to cure the epoxy resin.The flame-retardant properties of the composites were tested by thermogravimetric analyzer,cone calorimetry tester,limiting oxygen index(LOI),horizontal and vertical combustion,and electronic scanning electron microscopy(SEM).The results show that when 5 wt%flame retardant is added,the carbon residue of epoxy resin in the thermogravimetric test at 800°C increases from 2.2%to 19.8%.The LOI value increases from 23.7%to 32.8%.The peak heat release rate,total heat release,peak smoke release rate and total smoke release decrease by 34.9%,25.1%,22.2%,32.3%,respectively.Vertical combustion experiments have shown that the flammabilityrating of epoxy resin is increased from no to V-0 after the addition of flame retardant.SEM analysis of carbon residue after combustion shows that the addition of flame retardant could form a dense carbon layer on the surface of the epoxy resin during the combustion process to prevent combustion.The above tests fully demonstrate that the synthetic cardanol-based flame retardant has excellent flame-retardant and smoke suppression effect on epoxy resin.At the same time,the mechanical properties test on the electronic universal testing machine shows that the addition of flame retardant has little effect on the mechanical properties of epoxy resin and does not affect its use in many fields.