Effects of types and concentrations of modified Cloisite Clays on properties of chitosan nanocomposites for food packaging

Biodegradable chitosan has excellent film-forming properties compared to other biodegradables but also some limitations, such as poor water barrier and low mechanical strength. Thus, in this research, the effects of various types (Cloisite Ca, 15A, 20A, and 30B) and concentrations (0.5, 1, 2.5, and 5 wt%) of Cloisite on barrier, mechanical, structural and thermal properties on chitosan films were investigated. Cloisite was revealed to significantly lower the lightness (L*) depending on the type and concentration of Cloisite. The films containing Cloisite significantly improved oxygen barrier properties by 34.5%-73.6% compared to control, particularly Cloisite 30B. Cloisite 20A and Ca were found to significantly improve the water barrier by up to 84.61%, and Cloisite 20A and 30 B the tensile properties by up to 30%. The chitosan with less Cloisite content exhibited better smoothness and elongation. The dispersed Cloisite clays improved the thermal stability and enhanced the barrier and tensile properties of the chitosan with the increased Cloisite loading.