Burst and Physicochemical Characteristics of Glycerol-Added Chitosan Films for Food Packaging

Abstract

Toward establishing the full design aspects of chitosan as a packaging material or as cling wraps, the chemical characteristics, thermal stability, optical transparency, Young’s modulus, elongation at fracture, and burst strength of pure and glycerol-added 100 μm-thick-chitosan films were investigated. Films of chitosan and films with 10%, 20%, and 30% w/w glycerol as the plasticizer were prepared per standard protocols. Electron microscopic analysis revealed that all films are homogeneous. The addition of glycerol did not alter the crystallinity, lowered the glass transition by ∼7 °C, decreased the thermal stability, decreased the roughness by 50%, and increased the optical transparency by 5%. It was found that the incorporation of glycerol decreased the Young’s modulus by two orders, increased the plastic strain at least by four times, and decreased the burst strength by at least two times. The results from this systematic analysis, including comparisons with existing packaging materials, provide a holistic picture for tailoring the properties of chitosan-based packaging materials for modified atmosphere packaging (MAP) toward sustainable development.