How organo-montmorillonite truly affects the structure and properties of polypropylene

Polypropylene (PP)/organo-montmorillonite (OMMT) nanocomposites were prepared by using a highly effective PP solid-phase graft as compatibilizer. As a very low amount of PP graft was used, the properties of the PP matrix were maintained. The effects of the OMMT on the structure and properties of PP were studied fully. The intercalated structure of the nanocomposites was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD and TEM results showed that a typical intercalated structure was formed in the composites. The results of mechanical properties showed that the impact strength and the modulus of the nanocomposites were improved significantly compared with those of the neat PP. The thermal stability and crystallization of the nanocomposites were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The thermal stability of the nanocomposites, characterized by the initial decomposition temperatures, was substantially improved compared with that of the neat PP. The DSC results showed that the crystallization temperature of nanocomposites was increased compared with the neat PP. The viscoelasticity of the nanocomposites was studies by dynamic mechanical thermal analysis (DMTA). The DMTA results showed that the OMMT could improve the modulus of PP substantially. The T-g of PP was lowered by the incorporation of the OMMT. The changes of the properties were correlated with the formation of the PP/OMMT nanocomposites. (C) 2004 Elsevier Ltd. All rights reserved.