Physicochemical Characterization of Portuguese Clay and Nanocomposite Preparation with Polylactide

Abstract

A Portuguese clay (BRN) from the North East city of Bragança was collected and characterized in terms of health treatment and applied towards the preparation of nanocomposites with Polylactide (PLA). The silt-clay fraction of BRN is mainly composed of smectite with less illite, kaolinite and other minerals. The physicochemical properties are applicable for the topical applications and are mainly influenced by smectite. With the hazardous elements present, further bioavailability tests should be conducted. PLA nanocomposites with BRN and Wyoming montmorillonite SWy-2 (MMT) were respectively prepared through the solution casting method with ultrasonic stirring and using cetyltrimethylammonium bromide (CTAB) as the surfactant. The X-ray diffraction patterns show the exfoliated structures in most samples. Thermal gravimetric analysis reveals the increased thermal stability of the nanocomposites. The complexes were also characterized by nitrogen adsorption, infrared analysis and nuclear magnetic resonance for comparing the differences between BRN and MMT.