蒙脱土含量对聚乙烯/蒙脱土纳米复合材料动态流变行为的影响∗

摘要

Polyethylene(PE)/montmorillonite (MMT)nanocomposites with different MMT contents were pre-pared by in situ polymerization of ethylene with MMT and MgCl2 supported Ziegler-Natta catalyst.The effect of MMT content on the dynamic rheological behavior and melt flow index of PE/MMT nanocomposites have been studied by means of DHR-Ⅱdynamic rheometer and melt flow index indicator.The results show that the stor-age modulus,loss modulus,complex viscosity and flow activation energy of PE/MMT nanocomposite increase and then decrease,the melt flow index and tanδdecrease and then increase with the increases of MMT content, all above are lower than HDPE.When the MMT content is 4.58%,the tanδimproves,the melt flow index im-proves 489%,the flow activation energy decreases 22.4% by compared with HDPE,which is useful during molding process to the composite.%用有机蒙脱土(OMMT)/MgCl2负载 TiCl4的Ziegler-Natta插层型催化剂,通过原位聚合法制备了具有不同 MMT 含量的 P E/MMT 纳米复合材料.利用DHR-Ⅱ型动态流变仪和熔融指数(MFI)仪分析了MMT含量对其动态流变行为和熔融指数的影响.结果表明,随MMT含量的增加,复合材料的储能模量(G′)、损耗模量(G″)、复合粘度(η∗)和粘流活化能(ΔEη∗)先升高后降低且低于 HDPE；熔融指数(MFI)和损耗因子(tanδ)先降低后升高且低于 HDPE.相比于 HDPE,MMT含量为4．58％的复合材料,在高频区域 tanδ高于 HDPE；MFI 提高489％；ΔEη∗降低22．4％,该性质有利于 P E/MMT 纳米复合材料的成型加工.