席夫碱包覆植酸锌改性DOPO在环氧树脂中的阻燃作用

Flame retardancy of DOPO modified by zinc phytate coated with Schiff base in epoxy resin

以9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、3,4-二羟基苯甲醛和对苯二胺为原料,应用一锅法合成了含磷、氮的化合物PAPDO,并利用原儿茶醛的酚羟基与金属离子之间的作用力,将PAPDO包覆在植酸锌(ZnPA)表面制备出杂化阻燃剂(ZnPA@PAPDO)。以ZnPA@PAPDO为阻燃剂,双酚A型环氧树脂(EP)为基材,DDM为环氧固化剂,制备了阻燃环氧固化物EP/ZnPA@PAPDO,研究了ZnPA@PAPDO对EP阻燃性能的影响。热重结果显示:ZnPA@PAPDO的加入使复合材料的起始分解温度提前,促进聚合物成炭,表面形成炭层可以有效保护基体;ZnPA@PAPDO的加入可以增加高温时的残余量,EP/8%ZnPA@PAPDO的残留量增加了31.0%。另外,ZnPA@PAPDO的添加使EP复合材料的阻燃性能大大提高,EP/8%ZnPA@PAPDO的t1+t2为11.6 s,达到V-1级别,LOI值为32.8%。EP/ZnPA@PAPDO优异的热性能和阻燃性能归因于有机焦炭和金属保护层的双层阻隔作用、磷氮协效作用和自由基猝灭作用。

A compound(PAPDO)containing phosphorus and nitrogen was synthesized from 9,10-dihydro-9-oxa-10vphosphozaphene-10-oxide(DOPO),3,4-dihydroxybenzaldehyde and p-phenylenediamine in a one⁃pot method.A hybrid flame retardant(ZnPA@PAPDO)was prepared by coating PAPDO on zinc phytate using the force between the phenol hydroxyl group of protocatechualdehyde and metal ions.EP/ZnPA@PAPDO was prepared with ZnPA@PAPDO as the flame retardant,epoxy resin(EP)as the base material and diaminobenzene methane(DDM)as the epoxy curing agent.The effect of ZnPA@PAPDO on the flame retardant property of EP was studied.Thermogravimetric results showed that the addition of ZnPA@PAPDO advanced the initial decomposition temperature of the composite,promoted the charring of the polymer and formed a char layer on the surface to effectively protect the matrix.The addition of ZnPA@PAPDO can increase the residual amount at high temperature,and the residual amount of EP/8%ZnPA@APDO increased by 31.0%.In addition,the addition of ZnPA@PAPDO greatly improved the flame retardant property of EP.The t1+t2 of EP/8%ZnPA@PAPDO is 11.6 s,reaching V-1 level,and the LOI value is 32.8%.The excellent thermal and flame retardant properties of EP/ZnPA@PAPDO are attributed to the double barrier action of organic coke and metal protective layer,phosphorous nitrogen synergism and free radical quenching.