离子液功能化BNNS改性阻燃聚酯的合成研究

Synthesis of Ionic-liquid Functionalized BNNS Modified Flame Retardant Polyester

本文以六方氮化硼(h-BN)和离子液体(IL)为原料,采用原位剥离功能化技术,合成IL功能化氮化硼纳米片(BNNS@IL)。BNNS呈片层结构,厚度为5~10 nm。BNNS@IL起始分解温度为340℃,具有较好的热稳定性。阻燃性能测试表明,当BNNS@IL添加量为2wt%时,BNNS@I L-PET的极限氧指数(LOI)达到27%。相比纯PET样品,BNNS@I L-PET的热释放速率峰值(pHRR)、总热释放量(THR)和总烟释放量(TSP)分别降低17.25%、37.90%和25.90%。在此基础上复合1wt%聚磷酸铵(APP),其LOI值增加至30%,达到U L-94 V-1等级。与纯PET相比,pHRR和THR分别降低44.26%和50.14%,实现了更好的降热阻燃。残炭SEM及拉曼光谱分析表明,BNNS@IL同时存在BNNS的物理阻隔和IL催化成炭作用,APP的加入进一步促进PET脱水炭化产生连续致密的膨胀炭层,同时产生NH 3,实现气相和凝聚相的协同阻燃。

In this paper,hexagonal boron nitride(h-BN)and ionic liquid(IL)were used as raw materials to synthesize IL functionalized boron nitride nanosheets(BNNS@IL)by in-situ exfoliation functionalization technology.BNNS has a lamellar structure with a thickness of 5~10 nm.The initial decomposition temperature of the BNNS@IL is 340℃,and it has good thermal stability.The flame retardant performance test showed that the limiting oxygen index(LOI)of BNNS@I L-PET reached 27%when the BNNS@IL addition was 2 wt%.Compared with pure PET samples,the peak heat release rate(pHRR),total heat release(THR)and total smoke release(TSP)of BNNS@I L-PET were reduced by 17.25%and 37.90%,respectively.25.90%.On this basis,the LOI value of 1 wt%ammonium polyphosphate(APP)was compounded to 30%,reaching the U L-94 V-1 rating.Compared with pure PET,pHRR and THR were reduced by 44.26%and 50.14%,respectively,achieving better heat reduction and flame retardancy.SEM and Raman spectroscopy showed that BNNS@IL had both the physical barrier of BNNS and the catalytic char-forming effect of IL,and the addition of APP further promoted the dehydration and carbonization of PET to produce a continuous dense expanded carbon layer and NH 3 at the same time,realizing the synergistic flame retardant effect of gas phase and condensed phase.