Development and characterization of chitosan film incorporated with additives glycerol and gel for biodegradable packaging

The objective of this study was to isolate chitosan from shrimp shells using physical–chemical treatments and then evaluate the impact of additives on the chitosan matrix. Two different additives, glycerol and gel, were incorporated into the chitosan polymer using the casting process, and film thickness was measured to investigate the effect of additives on film properties. Scanning electron microscopy (SEM)-EDS was used to determine the morphology and percentage of elements in the film, while contact angle measurements were taken to assess the effect of film wettability on surface properties. The CT-gel sample exhibited a contact angle of 79.15° on the right and 78.17° on the left, which was crucial for CT, CT-gly, and CT-gly-gel. The mechanical behavior of the films was determined using a tensile test, and it was found that chitosan-glycerol systems had high transparency and homogeneity, with their properties depending on the content and types of additives. On the other hand, chitosan-gel systems had low transparency and a greenish hue, but were still homogeneous. Pure films and films with additives (CT, CT-gel, CT-gly, and CT-gel-gly) were found to be highly flexible due to their mechanical properties. These results provide insight into the role of additives in sample morphology and their impact on film properties, particularly for packaging applications.