Bioplastics from Shellfish Waste: Tuning the Tensile and Solubility Properties of Chitosan Films

Abstract

Chitosans of varying molecular weights were solubilized with acids (lactic, acetic, and malic) and formed into films with glycerin added as a plasticizer, with additional treatments applied to tune the solubility and tensile properties of the films. Lactic acid solubilized chitosan made films that had a wider range of tensile properties when tuned by the glycerin concentration. Neutralizing the films led to tensile strength increasing from 16.48 to 58.95 MPa, with a loss in strain at break percent decreasing from 47.95% to 28.19%. A plasticizer bath after neutralization of a glycerin-containing film leads to an increase in tensile stress from 17.97 to 26.44 MPa. The neutralized films without a plasticizer bath show a loss from 54.94 to 42.42 MPa in 98% humidity, while the neutralized sample with plasticizer decreases from 41.10 to 8.11 MPa. Having mechanisms for tunability of the properties increases the applicability of chitosan films as sustainably produced replacements for petroleum-derived plastics in single-use packaging, textiles, and many other applications.

Chitosan films made from shellfish food waste have tunable mechanical and solubility properties, leading to a wide breadth of applications.