Chitin and cellulose nanoparticles were isolated from shrimp shells, and wood pulp, respectively. The specific surface areas of these particles, measured by uptake of Congo red dye, ranged from 250 m²/g to 350 m²g depending upon the source material. The nanoparticles have been surface modified with different chemical groups ranging from aliphatic esters to ε-caprolactone oligomers. The goal is to modify the surface of the particles in such a way that their interaction with and dispersion in a thermoplastic matrix polymer leads to improved nanocomposite materials. Enhanced interactions and particle dispersions lead to better thermal and mechanical performance of the composite. Recent results in this area will be discussed.