Eucalyptus pulp cellulose fibers were modified by the sol-gel process for SiO2 superficial deposition and used as reinforcement of
thermoplastic starch (TPS). Cassava starch, glycerol, and water were added at the proportion of 60/26/14, respectively. For composites,
5% and 10% (by weight) of modified and unmodified pulp fibers were added before extrusion.The matrix and composites
were submitted to thermal stability, tensile strength, moisture adsorption, and SEM analysis. Micrographs of the modified fibers
revealed the presence of SiO2 nanoparticles on fiber surface.The addition of modified fibers improved tensile strength in 183% in
relation to matrix, while moisture adsorption decreased 8.3%. Such improvements were even more effective with unmodified fibers
addition.This result was mainly attributed to poor interaction between modified fibers and TPS matrix detected by SEM analysis.