This book discusses soy protein nanoparticle-based polymer blends, composites and nanoconposites aling with their chemistry, processing, preparation, characterization, applications as well as the soy protein-based materials rheology. After discussing the preparation of soy protein nanoparticles, the characterization methods such as atomic force microscope (AFM), transmission electron microscope (TEM) and scanning electron microscope (SEM), for the nanoscale soy protein reinforcements are examined. The various processing methods for nanocomposites and their mechanical, thermal properties, barrier properties are then discussed. The book then moves on to discussing the different types of blends, composites and nanocomposites with their type of polymer matrixes such as thermoplastics, thermoset, natural rubbers and synthetic rubbers.