Preparation And Characterization Of Styrene-ethylene Butylenes-styrene/polypropylene/organomontmorillonite Nanocomposites

Polymer nanocomposite is a kind of polymer filled with inorganic fillers. The nano-size (less than 100nm) inorganic particles disperse in polymeric matrix. Compared with traditional polymer blending material, the nanocomposite has its own advantages on the mechanical and thermal properties because of the nano-effect and the co-effect between nano-particles and the polymers. This provides a possibility for preparing new compounding materials with improved properties.The objective of the thesis is to study the various properties of thermoplastic elastomer styrene-ethylene butylenes-styrene (SEBS) blended of with thermoplastic polypropylene (PP). With addition of organomontmorillonite (OMMT), the mechanical properties of the polymer nanocomposite is studied, and the relationship between components, morphology, properties and use efficiency is established. A series of blends of SEBS/PP/MMT and SEBS/PP/OMMT are prepared. And their properties and microstructure are studied in detail in this thesis. Then an elementary relationship between microstructure and properties of is discussed. The main results are:1. OMMT was prepared by cation exchange of natural counter ions with ammonium surfactants, such as Hexadecyltrimethyl-ammomum bromide (C16). The nanostructure of SEBS/PP/OMMT hybrids was characterized by small-angel X-ray diffraction (SAXD), The d001 space of OMMT and SEBS/PP/OMMT hybrid increased from 1.30nm to 2.48nm and 4.07nm, respectively ,which indicate that the C16 and SEBS/PP could intercalate in the silicate layers and expand the basal spacing. At last the microstructure of the blends is studied by TEM.2. The mechanical properties of the blends, such as tensile strength, elongation, permanent compressed deformation and etc, are studied in this thesis. The result shows that the tensile strength and tear strength of SEBS/PP/OMMT polymeric nanocomposites are not improved obviously with the addition of OMMT, whereas the storage modulus is enhanced greatly.3. The dynamic mechanical property and thermal stability of SEBS/PP/MMT and SEBS/PP/OMMT are studied by DMA and TG. It was indicated that with Tg of PS blocks is increased from 61.7℃ to 89. 2 ℃ and Tg of EB blocks is rarely changed as OMMT added. These results...