有机改性蒙脱土的制备及其对聚乙烯-聚苯乙烯相态和力学性能的影响

利用Gemini表面活性剂对蒙脱土进行插层改性制备得到有机改性蒙脱土（OMMT），采用溶液混合法制备了OMMT/聚苯乙烯（PS）母料，将OMMT/PS母料与聚乙烯（PE）熔融共混制备得到OMMT/PS-PE复合材料。研究了蒙脱土的插层改性对OMMT/PS-PE复合材料相形态和力学性能的影响。对OMMT进行FTIR、XRD、TG表征，结果表明Gemini表面活性剂成功插层进入蒙脱土层间。通过SEM和电子万能试验机研究了OMMT/PS-PE复合材料相结构、分散相粒径的及相态与力学性能之间的关系。结果表明，随着OMMT含量的增加，PS分散相的粒径逐渐减小；当OMMT含量为2.5wt%时，OMMT/PS-PE复合材料的相形态由“海-岛”转变为双连续结构。与未添加OMMT的PE-PS树脂相比，OMMT/PS-PE复合材料弯曲模量和断裂伸长率显著提高，分别提高了约18%和近50倍。 

Preparation of organic modified montmorillonite and its effect on phase morphology and mechanical properties of polyethylene-polystyrene

Organic modified montmorillonite (OMMT) was prepared by intercalation modification of montmorillonite with Gemini surfactant. The OMMT/polystyrene (PS) composites were fabricated through solution mixing. The OMMT/PS composites and polyethylene (PE) were melt-blended to obtain OMMT/PS-PE composites. The effect of OMMT on the mechanical properties and phase morphology of OMMT/PS-PE composite was analyzed. The characterizations of OMMT by FTIR, XRD and TG show that Gemini surfactant is successfully intercalated into the layer of montmorillonite. The morphological structure of OMMT/PS-PE composites and the changes of the particle size of PS dispersed phase, as well as the relationship between the phase morphology and the mechanical properties were examined by SEM observation and electronic universal testing machine. The results demonstrate that the particle size of the disperse phase gradually decreases with the addition of OMMT. The phase morphology of the OMMT/PS-PE composites changes from "sea-island" to co-continuous structure when the content of OMMT reaches to 2.5wt%. Compared with PE-PS matrix without OMMT, the flexural modulus and elongation at break of OMMT/PS-PE composites are significantly improved, and increases more than about 18% and 50 times, respectively.