TiO2 nanofillers (5 nm, 0-15% weight) have been introduced in the PMMA matrix using a twin screw extruder to increase the performance of PMMA. The twin screw extrusion process is optimized to disperse the particles into PMMA. Nanofiller infusion improves the thermal, mechanical, and UV absorption properties of PMMA. TiO2-PMMA nanocomposites exhibit the increase in tensile modulus (90%), decomposition temperature (31%), dimension stability (similar to 60%) and UV absorption (similar to 410%). Properties of the nanoTiO(2)-PMMA composites are depending on the dispersion of TiO2 in the PMMA matrix. It is interrelated with loading. Formation and disappearance of the peaks in FTIR confirm the chemical interaction of PMMA with TiO2. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 2890-2897, 2010