Preparation of Chitosan with Different Characteristics and Its Application for Biofilms Production

摘要

In this research, different chitosan samples were obtained and were applied to produce biopolymeric films, aiming to obtain environmentally friendly materials for packaging applications. Chitosans were obtained by different conditions from the alkaline deacetylation of chitin. The chitosan films were prepared from all chitosan samples by casting technique. The results showed that the molecular weight of chitosan samples increased as a function of the increase in the chitin diameter and of the decreases in the NaOH:chitin ratio, NaOH concentration and reaction time, and its values were in the range from 101 to 201 kDa. For the deacetylation degree of chitosan an inverse behavior was observed, and its values ranged from 64.0 to 95.9 %. The best values were obtained for the films when chitosan with highest molecular weights and lowest deacetylation degrees were used. In this condition, the film was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and thermal analysis (TGA and DSC). The films produced had physical-mechanical properties acceptable for use in active food packaging.