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

THE DEVELOPMENT OF NANOSTRUCTRUCTURED POLYMETHILMETHACRYLATE (PMMA) SURFACES WAS STUDIED BY THE INCORPORATION OF SILICA, ALUMINA AND SILICA-ALUMINA, THE FORMER OBTAINED BY SOL-GEL PROCEDURE. THE MATERIALS WERE OBTAINED IN A POLYMER SOLUTION (ACETONE, ISOPROPANOL) AND CONTAINS VARIABLE AMOUNTS OF THE INORGANIC COMPONENT (10 AND 20 % IN THE MASS). THE SEM STUDIES SHOW THE MODIFICATION OF THE POLYMER STRUCTURE BY THE ADDITION OF THE SILICON OXIDE AND ALUMINUM OXIDE; THOUGH NOT ALL THE SAMPLES SHOW A HIGH DISPERSION OF THE INORGANIC COMPONENT. THE FT-IR SPECTRUM SHOWED A REDUCTION IN THE INTENSITY OF THE CARBONYL SIGNAL ASSOCIATED TO THE POLYMER, DUE TO THE INCORPORATION OF THE FILLER AND THE PRESENCE OF BANDS ATTRIBUTED TO THE INORGANIC COMPONENTS INCORPORATED. THROUGH TGA AND DSC STUDIES THE MODIFICATION OF THE THERMAL STABILITY OF THE POLYMER WAS PROVED, DEPENDING ON THE INORGANIC COMPONENT USED AND ITS COMPOSITION.

POLYPROPYLENE COMPOSITES WITH 5 TO 10% OF SIO2, AL2O3 Y TIO2 NANOPARTICLES WERE SYNTHESIZED. THE OXIDES WERE OBTAINED USING THE SOL-GEL TECHNIQUE AND WERE ADDED TO THE MOLTEN POLYPROPYLENE. THE MORPHOLOGY OF NANOPARTICLES WAS OBSERVED BY SCANNING ELECTRON MICROSCOPY AND SHOWED THAT THE INCORPORATION OF TIO2 AND SIO2 GELS PRODUCES HIGH DISPERSION OF THE FILLER, WHILE THE USE OF AL2O3 RESULTS IN AGGREGATES OF THESE NANOPARTICLES IN THE POLYMER MATRIX. THE X-RAY DIFFRACTOGRAM OF THE COMPOSITES REVEALED A DISPLACEMENT OF CHARACTERISTICS LINES OF POLYPROPYLENE AND AN INCREMENT OF THE INTERPLANAR SPACES, INDICATING SOME INTERACTION BETWEEN THE COMPONENTS AND THE PREDOMINANCE INTERCALATION OF OXIDES. THROUGH FT-IR IT WAS NOTICED THE PRESENCE OF FUNCTIONAL GROUPS ATTRIBUTABLE TO THE FILLER NANOPARTICLES. THE CRYSTALLIZATION, THE FUSION BEHAVIOUR AND THE THERMAL STABILITY OF THE COMPOSITES WAS STUDIED USING DIFFERENTIAL SCANNING CALORIMETRY AND THERMOGRAVIMETRIC ANALYSIS IT WAS FOUND A REDUCTION IN THE CRYSTALLIZATION TEMPERATURE AND INCREMENT IN THE THERMAL STABILITY OF THE POLYPROPYLENE MATRIX DUE TO THE ACTION OF THE SILICA, ALUMINA AN TITANIA NANOPARTICLES.