钙基蒙脱石对聚苯乙烯纳米复合材料阻燃性能的影响

Effect of modified Ca-montmorillonite on flame resistance of PS nanocomposites

钙基蒙脱石(Ca MMT)是自然界存在的主要蒙脱石形态。分别采用十六烷基三甲基溴化铵(CTAB)和双十二烷基二甲基溴化铵(DDAB)对Ca MMT进行插层改性,制备了有机钙基蒙脱石(Ca OMT)。采用熔融共混法制备了聚苯乙烯(PS)/Ca OMT纳米复合材料。通过X射线衍射法评估了Ca MMT的改性效果;采用热重法和锥型量热法研究了复合材料的热稳定性和燃烧过程中的释放速率、生烟速率以及CO释放速率等阻燃性能。研究表明,CTAB和DDAB均可对Ca MMT有效插层改性,其中,DDAB改性的Ca MMT对PS的阻燃性能提高较大。与纯PS相比,PS/Ca OMT纳米复合材料的相对最大热释放速率可降低42.9%,生烟速率可降低7.5%,CO释放率可降低16%。

The main form of montmorillonite in nature is calcium montmorillonite （CaMMT）. In this article, CaMMT was modified with cetyltrimethyl ammonium bromide （CTAB） and didodecyl dimethyl ammonium bromide （DDAB） by intercalation method to get the organically modified calcium montmorillite （CaOMMT）. Then the polystyrene（PS）/CaOMMT nanocomposites were prepared by melt blending method. The modification effect of CaMMT was evaluated by X-ray diffraction, and the thermal stability, heat release rate （HRR）, smoke produce rate （SPR） and CO release rate （CORR） of the composite were characterized by thermogravimetric analysis and cone calorimeter. The results show that the CaMMT can be intercalated well with CTAB and DDAB. The better improvement on flame resistance of PS nanocomposites was achieved by modifired CaMMT with DDAB. Compared with pure PS, the peak HRR, SPR and CORR of the PS/CaOMT nanocomposites can decreased by 42.9%, 7.5% and 16%, respectively.