Exfoliation of bentonite clay by ultrasonication and evaluation of the polypropylene-based composites manufactured thereof

Abstract

Clays are layered structure and the layers can be separated by mechanical or chemical processes. In the present study, bentonite clay (BC) has been exfoliated by ultrasonication with distilled water as a medium. Sonication has been carried out for 30, 60 and 120 min. The clay samples have been characterized by X-ray diffraction, scanning electron microscopy and thermal analysis for phase, morphology and thermal stability, respectively. Sonication for 60 min leads to a better exfoliation and reduction in particle size of the clay. The clay powders have been utilized to prepare composites with polypropylene (PP). Compounding has been performed using a twin screw extruder by melt mixing technique and composite specimens have been prepared by the injection moulding technique. Tensile strength, Izod impact strength, hardness along with density have been evaluated for composites. It has been observed that the sample prepared with BC sonicated for 60 min shows the optimum properties due to better exfoliation of clay. Enhancement in tensile and impact strength has been 10.2% and 11.9% for the aforementioned composite as compared to untreated bentonite clay-based composite.