Biocomposites based on chitosan and carnauba straw powder

Abstract

In this study carnauba straw powder was submitted to chemical treatments using alkali (NaOH) or hexane, in order to increase its hydrophilicity and to investigate its potential use for the development of a biodegradable composite. Biocomposites were prepared in solution, using carnauba straw powder and chitosan as matrix, with powder contents of 10 and 50 wt %. Both, straw powder and biocomposites, were characterized by chemical composition analysis, FTIR, TGA, DSC and SEM. According to the results, the chemical treatment using NaOH was efficient in removing the soluble components of the powder and cleaning its surface. DSC analyses demonstrated that the addition of high powder loadings does not reduce the thermal stability of the composite. The elastic modulus of the biocomposites obtained with 10 wt % of untreated carnauba powder remained unaltered, decreasing for a filler content of 50 wt %. The effect of NaOH chemical treatment was more evident for the composite with 50 wt % of powder.

Keywords

• Biocomposites
• carnauba straw powder
• chitosan
• chemical treatment