Clay/Polyethylene Composites with Enhanced Barrier Properties for Seed Storage

Abstract

The utilization of clays to enhance the water vapour barrier properties of polyethylene requires knowledge about factors associated with the constituents themselves. Hence, this paper presents combinations of two types of polyethylene and five different clays. Morphological, mechanical and thermal properties related to the water vapour permeability of clay/polyethylene composites were investigated. Although no evidence of clay exfoliation was observed according to morphological and spectral results, it was found that the enhanced water vapour barrier properties were linked to clay aspect ratio, composites interface, polyethylene crystallinity and storage conditions. The best water vapour barrier properties were obtained by increasing polyethylene crystallinity with unmodified clay of high aspect ratio. Organoclays addition showed no improvement in barrier properties of polyethylene unless the interface was strongly compatibilized. Contrary to the results published elsewhere, clay addition brought about no mechanical improvements to polyethylene tested.