Organofilização de argilas bentoníticas e aplicação no desenvolvimento de nanocompósitos com matriz de polipropileno.

Abstract

In this work, polypropylene-bentonite and polypropylene-compatibilizerbentonite nanocomposites were prepared by melt intercalation method using a modular co-rotational twin screw extruder and a counter rotating twin screw extruder attached to a HAKE torque rheometer. Initially, Brasgel PA and Cloisite Na+ bentonitic clays were organophilized with ionic and non-ionic surfactants with the aim of obtaining organophilic clays. The clays were characterized by XRay Fluorescence (XRF), laser diffraction and Infrared Spectroscopy (FTIR). FTIR and DRX results showed that the ionic and non-ionic surfactants were incorporated into the clay, confirming the organophilization. Subsequently, the organophilic bentonitic clays were incorporated into PP H103, PP H503 and PP/PP-g-MA. Nanocomposites formation as well as the properties of PP/organophilic clay and PP/organophilic clay/PP-g-MA mixtures were verified by DRX, Optical microscopy (OP), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Thermogravimetry (TG), Heat Distortion Temperature (HDT), flammability test and tensile and impact strength tests. Form the results obtained through XRD, OM, MEV, MET analyses, the method used and the processing conditions, it may be concluded that it is possible to develop nanocomposites with mixed structure (agglomerates, tactoids and exfoliated particles) with predominance of an intercalated structure. The processing conditions (screw type, feeding rate and screw speed), matrix viscosity, concentration and type of the bentonite clay and PP-g-MA concentration had little effect on the nanocomposite obtention and on its properties, in general.