席夫碱式磷氮膨胀型阻燃剂的制备及应用

Preparation and Application of Schiff Base Phosphorus-Nitrogen Intumescent Flame Retardant

采用一步法将对苯二甲醛分别与二乙烯三胺和4,4’-二氨基二苯甲烷反应生成聚席夫碱,再通过加成反应在席夫碱分子链中加入9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物,制备了两种新型的磷氮膨胀型阻燃剂PED和PDD,并对两种阻燃剂进行了表征。通过差示扫描量热仪发现这两种阻燃剂与尼龙6(PA6)有很好的相容性。当这两种阻燃剂与PA6熔融共混时,表现出良好的阻燃性能。当添加量为15%时,PA6复合材料达到UL94 V-0级,极限氧指数分别为27.2%和27.6%,600℃时的残炭量分别为2.3%和5.3%,PDD体系表现出更好的阻燃性能。扫描电子显微镜观察到炭渣表面致密,致密的结构很好地阻止了热量传递,保护了基体内部。动力学分析表明,阻燃剂的加入并没有牺牲PA6的稳定性,而且提高了材料的阻燃性能。同时,PDD阻燃复合体系表现出了更好的稳定性。

Poly(schiff base)s were synthesized through a one-step procedure from p-phthalaldehyde with diethylenetriamine and 4,4'-diaminodiphenylmethane respectively.Then two kinds of new phosphorus nitrogen intumescent flame retardants PED and PDD were prepared by adding 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide into the molecular chain of poly(schiff base)s through addition reaction and characterized.The finding of differential scanning calorimetry indicate that the two flame retardants has good compatibility with nylon 6(PA6)and their blends exhibit good flame retardancy.When the amount is 15%,flame retardancy of PA6 composites reach UL94 V-0,and limited oxygen index arrive at the value of 27.2%and 27.6%respectively.Concurrently,the carbon residue at 600℃are 2.3%and 5.3%respectively.PDD systems exhibit better flame retardant properties.The results from scanning electron microscope suggest that the surface of carbon slag became dense,which prevent heat transfer and protect the interior of the matrix.The kinetic analysis indicate that the incorporation of flame retardant does not sacrifice the stability of PA6,but also improves the flame retardancy of the material.At the same time,PDD flame retardant composite system show better stability.