原位聚合阻燃耐高温尼龙PA10T10DDP的合成和性能

Synthesis and Properties of In-situ Polymerized Flame Retardant High Temperature Nylon PA10T10DDP

将反应型磷系阻燃剂[(6-氧代-6H-二苯并[C,E][1,2]氧磷杂己环-6-基)甲基]丁二酸(DDP),以原位聚合的方式共聚到耐高温尼龙聚对苯二甲酰癸二胺(PA10T)的主链中,得到原位聚合阻燃耐高温尼龙PA10T10DDP,通过优化聚合反应工艺,提高PA10T10DDP的分子量。PA10T10DDP的傅里叶变换红外光谱表明,DDP成功接入PA10T的主链中;在热学性能方面,PA10T10DDP初始热分解温度仍高于380℃,具有较好的热稳定性和相对较低的熔点;极限氧指数(LOI)和垂直燃烧法阻燃等级测试结果表明,与共混阻燃改性PA10T相比,PA10T10DDP阻燃性能明显提升,阻燃剂DDP质量分数为8.5%时,PA10T10DDP阻燃等级为V-0级,LOI为35%。通过分析燃烧后的炭层,可以将PA10T10DDP优异的阻燃性能归结为气相阻燃和凝聚相阻燃的协同作用。采用扫描电子显微镜对PA10T10DDP冲击断面进行观察,发现断面均匀,无阻燃剂的团聚和析出,实现分子级别的阻燃改性,因此,PA10T10DDP的力学性能与PA10T相接近,阻燃剂DDP的引入对力学性能的影响较小。

The reactive phosphorus-based flame retardant 9,10-Dihydro-10-(2,3-dicarboxypropyl)-9-oxa-10-phosphaphenanthrene 10-oxide(DDP)was copolymerized in the main chain of the high temperature resistant nylon poly(decamethylene terephthalamide)(PA10T)by in-situ polymerization to obtain PA10T10DDP.The molecular weight of PA10T10DDP was improved by optimizing the polymerization process.The FTIR spectroscopy of PA10T10DDP shows that DDP is successfully inserted into the main chain of PA10T.In terms of thermal properties,initial thermal decomposition temperature of PA10T10DDP is over 380℃,and has better thermal stability and relatively lower melting point.Limiting oxygen index(LOI)and vertical combustion tests show that PA10T10DDP exhibits excellent flame retardant properties compared with those of PA10T,at the same flame retardant DDP content of 8.5wt%,the flame retardant level and LOI of PA10T10DDP are V–0 and 35% respectively.By analyzing the carbon layer after combustion,the excellent flame retardancy of PA10T10DDP can be attributed to the synergistic effect of gaseous phase flame retardant and condensed phase flame retardant.The impact fracture section of PA10T10DDP was observed by SEM,and it is found that the fracture section is uniform,no agglomeration and precipitation of flame retardant,which means molecular-level flame retardant modification is realized.Therefore,the mechanical properties of PA10T10DDP are similar to those of PA10T,and less affected by the introduction of flame retardant DDP.