UV-Shielding films of bacterial cellulose with glycerol and chitosan. Part 1: equilibrium moisture content and mechanical properties

Bacterial cellulose films were combined with glycerol and chitosan to improve the UV-barrier and mechanical properties. In part 1, the moisture content and mechanical properties (tensile and puncture properties) were analysed by response surface methodology. The calculated values of the mechanical properties were in the range of 1.23-39.28 MPa for tensile strength, 2.28-25.34% for percentage of elongation, 11.72-1579.59 MPa for Young's modulus, 0.22-1.92 MJ/m 3 for toughness, 43.74-1067.35 g for burst strength and 0.39-3.12 mm for distance to burst. In general, a plasticizing and a reinforcing effect on the bacterial cellulose films was observed by glycerol and chitosan addition. Glycerol provided adhesive properties, which can be an advantage for application on foods, such as fruit or vegetables, as a wrapping material.