Physicochemical properties and film formation of the chitin hydrocolloid fabricated by a novel green process

Abstract

AbstractChitin is a valuable natural material, but its applications are limited because of its insolubility in water. Size reduction of natural materials has been found to offer certain benefits, including enhancing dispersibility. We employed media milling to produce a chitin micro‐suspension with water as the sole solvent, and to fabricate the chitin film. The particle size and molecular weight were decreased from 96.86 to 21.95 μm and 173 to 75 kDa (Mn), respectively, post milling; however, the degree of deacetylation slightly increased (from 21.26 to 24.31) with milling time. Moreover, limited water‐soluble fractions were generated, the quantity (1.5–2.0% d.b.) and molecular weight (Mn 15–34 kDa) of which were characterized. These fractions enabled the formation of a chitin film through the induction of hydrogen bonds. The particle size affected the morphology and mechanical properties of the film. The fabricated chitin film had tunable thickness (61.3–80.7 μm), tensile strength (38.95–64.61 MPa), elongation (0.93%–2.16%), Young's modulus (2994–4246 MPa), WVP (12.04–17.79 g mm/m2 day kPa), swelling ratio and surface smoothness. This novel method for fabricating chitin films through aqueous suspension can improve applications of chitin in packaging and particularly fulfill environmentally friendly requirements.