Efeito da incorporação de sílica tratada com aminosilano nos nanocompósitos PMMA/SAN/Sílica

Abstract

Research on nanocomposites of polymers and silica has become the focus of many researchers in recent years because of the excellent properties presented when compared to individual components. In this work a surface modification treatment of silica with 3-aminopropyltriethoxysilane (APTES) was carried out for incorporation in the poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blend by processing in a twin screw extruder. The effect of the addition of silica nanoparticles with and without surface modification on the structure and properties of the PMMA/SAN blend was evaluated, aiming to promote better mechanical properties without compromising the transparency of the materials produced. The materials were characterized by flow index measures (MFI), mechanical tests of uniaxial traction, 3-point flexure, Rockwell M hardness (HRM) and Shore D, Izod impact, parallel plate rheometry, transmission electron microscopy (TEM), abrasion and scratch tests. The rheological results indicated that there was a reaction between the silica nanoparticles treated with the pure polymers and with the PMMA/SAN blend, showing a useful technique to evaluate possible reactions during the extrusion process. The nanocomposites showed a decrease in the properties of maximum tensile strength, impact strength and elongation at break when compared to PMMA/SAN blends, which showed synergism in the properties of maximum tensile strength and elongation at break. However, the properties of the nanocomposites with modified silica nanoparticles were superior to the nanocomposites without treatment. The addition of treated silica promoted an increase in the modulus of elasticity, hardness, abrasion and scratch of the nanocomposites produced.