Effect of degree of deacetylation and molecular weight on physicochemical properties of chitosan films

Chitosan is a linear natural polymer obtained by deacetylation of chitin using sodium hydroxide. Depending on the manufacturing process as well as its source, chitosan is commercially available in various types and grades with molecular weights (MW) ranging from 38 to 200 kDa and degree of deacetylation (DD) with a range between 60 to 100%. In this work, chitosan films of different degrees of deacetylation (DD) and molecular weights (MW) were prepared by the solution casting method at concentrations of 1%, 2%, and 3%. The influence of DD and MW were studied on the prepared films using various characterization techniques such as dressing pH, water absorption capacity, water vapour transmission rate (WVTR), porosity, and water contact angle (WCA). The water absorption capacity, water vapour transmission rate (WVTR), and porosity results showed that there were significant effects of DD, MW, and concentration on the above-mentioned films.