Effect of nanoclay and ethyl-Nα-dodecanoyl-l-arginate hydrochloride (LAE) on physico-mechanical properties of chitosan films

• Nanoclay and LAE addition changed chitosan film properties.
• Nanoclay addition to films decreased the crystallinity.
• Presence of nanoclay in films reduced the water solubility.
• Nanoclay increased elongation at break of chitosan films.
• Presence of LAE and/or nanoclay increased the tensile strength.

Chitosan films have good barrier properties to gases, but present high water vapor permeability. The addition of a nanoclay (Cloisite®30B) was studied to improve the water vapor permeability and mechanical properties of chitosan films, and ethyl-Nα-dodecanoyl-l-arginate hydrochloride (LAE) was added as an antimicrobial agent. Chitosan-acetate films were prepared by solvent casting technique from chitosan solutions (20 g/L) with different combinations of nanoclay (0–5–10 g/L) and LAE (0–0.5–1 g/L) by using an experimental design of 32. Physical properties were evaluated and the results showed different thickness for all films (0.058–0.084 mm). Moisture content (25.2–34.0 g/100 g), water solubility (29.0–47.2%), water vapor transmission rate (1.81 × 10−3–2.34 × 10−3 kg s−1m−2) and crystallinity decreased significantly in the films with high concentration of nanocompound, due to clay layers constitute a barrier to gases and water. The elongation at break (49.6–66.3%) and tensile strength (6.7–9.0 MPa) increased significantly. Chitosan film with 10 g/L of nanoclay and/or 1 g/L of LAE gathered the best physico-mechanical properties.