Nano-addition of raw bentonite enhances polypropylene (PP) properties

Abstract

Bntonite (BNT) is the cheapest raw material source for making commercial nanoclay, which is approximately 250 times more expensive than BNT. Perhaps this may be one of the reasons why we do not find a translation of good scientific work on polymer nanocomposites into commercial reality. In this work, it is demonstrated that PP nanocomposites were made using 3% raw bentonite via Master batch (MB) route with maleated PP. This product has 9.5% greater tensile strength, 18.6% greater flexural strength, and 27% greater flexural modulus than neat PP. The repeat extrusion of PP/bentonite was carried out, which had beneficial effects on tensile modulus and flexural strength and less so on other properties. This study opens a Pandora's box full of possibilities, such as cheap polymer nanocomposites being available for many different applications. Increase in the previously mentioned properties of PP-BNT adduct cannot be explained by the nucleation effect of BNT on PP. X-ray diffraction, internal surface area, TGA, and DSC measurements were made on the above samples. Addition of 3% raw bentonite increases the crystallization of PP by 7.5°C (nucleation effect). Since this is just a pilot study, this opens a vast commercial scope for making nanocomposites from raw clays. The stakes for doing this are very high, because BNT is $0.10/kg and can be available consistently from mineral producers in Gujarat and Rajasthan in India. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1004–1009, 2006