The book focuses on clay-based micro and nanocomposites with different synthetic polymers and presents their synthesis, characterization and testing. Keywords: Synthetic Polymer Composites, Nanoclay-based Polymer Nanocomposites, Hectorite, Nontronite-Starch, Reinforcement of Thermoplastics, Polyethylene, Polypropylene, Sonochemical Synthesis, Drug Delivery, Electromagnetic Interference Shielding, Flame Retardancy, Water Treatment.