The book focuses on clay-based micro and nanocomposites with different synthetic polymers and presents their synthesis, characterization and testing. The fields of application of these materials include food packaging, rheological control agents, wastewater treatment, biomedical applications and drug delivery. 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