Investigation of the effectiveness of nanocellulose extracted from Sri Lankan Kapok, as a filler in Polypropylene polymer matrix

Abstract

Kapok (Ceiba pentandra) is a commonly available plant in Sri Lanka. Its application in waste water treatment, biomedical field and domestic uses is numerous. The purpose of this research is to investigate the effectiveness of nanocellulose extracted from Ceiba pentandra, as a filler in Polypropylene polymer matrix. Nanocellulose extracted from acid hydrolysis was further treated to avoid deterioration of its strengths and to increase its compatibility with the polymer matrix. The morphology of the extracted cellulose was studied under scanning electron microscopy, which revealed the existence of nanofiber and flakes of thickness in the nano dimension between 100 nm to 1000nm. Composites of Polypropylene and nanocellulose were prepared by extrusion. Mechanical, thermal, morphological and physio chemical properties of the composites were tested. The PP/cellulose composites demonstrated a remarkable improvement of tensile modulus and tear resistance. However lack of interfacial interactions detrimentally affected certain mechanical properties. The effect of dispersion of filler on mechanical properties was also briefly studied by comparing results of mechanical tests of composites prepared at different speeds and residence times in the extruder. Significant changes in the thermal properties weren't noted, although a slight improvement of the initial decomposition temperature was noted in the thermal gravimetric analysis. The distribution of the filler in the polymer matrix was observed from which nano level dispersion was observed. X-Ray diffraction was carried out to determine the crystallinity of the extracted cellulose.