Nanoclay Modification and Functionalization for Nanocomposites Development: Effect on the Structural, Morphological, Mechanical and Rheological Properties

During the last decades, a widespread research has been devoted to organically modified clay minerals as reinforcements for polymer matrices. The most commonly used procedure to prepare organophilic clay is the cation exchange reaction with ammonium surfactant. Nevertheless, this kind of surface modification does not provide an efficient covalent bond between clay minerals and polymer matrices. For these reason, wide variety of silane coupling agents has been used to achieve compatibility and good dispersion between the hydrophilic clay and hydrophobic polymer. In this respect, the obtained polymer/organoclay nanocomposites exhibit significant improvements in their physical and mechanical properties over those of raw polymers. Herein, this chapter is divided into two parts. In the first part, it focus on the effect of silane modification of different clays minerals namely Halloysite, Montmorillonite and Sepiolite by various organosilanes such as 3-aminopropyltrimethoxysilane (A), 3-iodopropyltrimethoxysilane (I), 3-mercaptopropyltrimethoxysilane (S) and triethoxyvinylsilane (T). Although the silylation method, characterization and properties of the silane grafted clays are discussed. The second part is devoted to the preparation of polymer/silane grafted clay nanocomposites by melt compounding using polypropylene as polymer matrix. From the nanocomposites with 3wt% concentration in terms of silane grafted clay produced, the morphological, physical, mechanical, and rheological properties were measured. The results showed that the overall properties of silane grafted clays nanocomposites were increase which is attributed to better interfacial adhesion.