Characterization of cassava starch films plasticized with glycerol and strengthened with nanocellulose from green coconut fibers

The aim of this study was to obtain and characterize biodegradable films of cassava starch plasticized with glycerol and reinforced with nanocellulose from coconut fibers. The mechanical and physical-chemical properties of the nano-biocomposites films obtained were evaluated. The method used to investigate the viability of incorporating coconut nanocellulose in films was applied through a statistical design of the response surface of 17 formulations containing three independent variables (starch, glycerol and nanocellulose). The films were prepared through casting technique, and the effect of different concentrations of the ingredients in each formulation was investigated by monitoring the dependent variables. The green coconut fiber was composed of 32% cellulose, 38% lignin and 0.25% hemicellulose resulted in nanocellulose with a length (L)/diameter(D) value of 38.9±4.7 after the acid hydrolysis process (64% H2SO4; 50°C; 10-15 min). The incorporation of nanocellulose resulted in significant changes (p<0.05) in the barrier and mechanical properties. Additionally, there was a significant increase in the Young’s modulus and in the tensile of the nano-biocomposites. Consequently, there was a decrease in the percentage of elongation. Thus, films formulated from cassava starch plasticized with glycerol could have significantly altered mechanical, technical and barrier properties due to the incorporation of coconut nanocellulose. Key words: Biodegradable packaging, cellulose nanocrystals, nano-biocomposites, coconut fibers.