Mechanical, Thermal and Barrier Properties of Starch-based Films Plasticized with Glycerol and Lignin and Reinforced with Cellulose Nanocrystals

The development of degradable polymer blends using natural additives emerges as a solution to the issue of high cost of biodegradable materials. In these blends, natural additives such as starch, cellulose, lignin, among others, are mixed with conventional plastics. This study aims to evaluate the thermal, mechanical and barrier properties of flexible thermoplastic films of corn starch using glycerol and lignin as plasticizer and cellulose nanocrystals (CNCs) as reinforcement. It was observed that the presence of lignin and 1% CNCs effectively increased the maximum stress and the modulus of elasticity of about 265% and 1274%, respectively, when comparing to the film containing only glycerol as well as an improvement on the barrier properties. The presence of lignin provided an improvement in the thermal stability of the material. Therefore, the flexible films produced are promising materials due to their low production cost, biodegradability and high mechanical and barrier performance.