Preparation Of Organically Modifid Montmorillonite And Its Application In Polymers

Montmorillonite (MMT) is a layered silicate, having excellent mechanical properties, thermal properties and gas barrier properties, and is widely used in the preparation of polymer/layered silicate nanocomposites (PLS). But the interlayer spacing of unmodified MMT is small, having poor compatibility with polymer; it must be modified in order to broaden its field of application.Montmorillonite (MMT) was modified by using epoxy resin to obtain the organic montmorillonite (OMMT). OMMT were prepared through melt intercalation method. X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA) were used to study the sturcture and thermal stability of OMMT. It was found that the interlayer spacing of the epoxy resin modified OMMT significantly increases. The interlayer spacing of OMMT increased with the increase of epoxy resin content. The thermal degradation temperature of OMMT at 10 wt% weight loss was up to 380℃.The effect of OMMT content and PA6 molecular weight on mechanical and thermal properties of PA6/OMMT nanocomposites was studied. Differential scanning calorimeter (DSC), transmission electron microscope (TEM) and XRD were used to study the melting and crystallization behavior, and the morphology of PA6/OMMT. With the increase of OMMT content, strength, modulus and heat distortion temperature of PA6/OMMT nanocomposites increased. Epoxy resin modified OMMT can improve the thermal stability of PA6. PA6/OMMT nanocomposites based on the higher molecular weight PA6 yielded superior mechanical properties. OMMT can promote the formation of y crystalline of PA6 and play the role of heterogeneous nucleation in the crystallization process. OMMT was dispersed well in the PA6/OMMT nanocomposites when OMMT content was 5wt%. The dispersion of OMMT was improved when the high molecular weight of PA6 was used as matrix.The effect of OMMT content on mechanical and thermal properties of PP/OMMT and PC/OMMT nanocomposites was studied. Differential scanning calorimeter (DSC), transmission electron microscope (TEM) and XRD were used to study the melting and crystallization behavior, and the morphology of PP/OMMT and PC/OMMT. It was found that the epoxy resin modified OMMT dispersed well in the PP/OMMT and PC/OMMT nanocomposites.