Morphological and mechanical characterization of high-strength sulfur composites prepared with variably-sized lignocellulose particles

Abstract

The extent to which lignocellulose biomass particle size influences the properties of biomass-sulfur composites prepared from these particles was evaluated. For this purpose several materials were prepared by the reaction of sulfur with peanut shell particles that had been fractionated into narrow size ranges using ASTM certified sieves. Eight particle size fractions with an upper cutoff range of 710 microns were thus used to prepare a series of eight composites PSS-1 to PSS-8. The use of biomass particles having defined size ranges allowed for a 36-fold faster reaction rate relative to the analogous reactions employing unfractionated biomass, while the resultant composites still maintained excellent strength characteristics. Composites prepared with smaller biomass particles exhibited the most uniform dispersion, yet similar ultimate strength characteristics were observed for most of the composites irrespective of the biomass particle size. The strength characteristics of these materials could be rationalized by the interplay of the dispersion of filler in the network versus the unfavorable interactions between the hydrophilic biomass filler and hydrophobic sulfur network. This work highlights the importance of quantifying filler effect for microscopically non-homogeneous composite materials and provides insight on simple strategies for drastically impacting the time and energy expenditures for biomass composite synthesis and resultant properties.