Physico-chemical, thermal, and mechanical approaches for the characterization of solubilized and solid state chitosans

International audience; This study was conducted on the both solid and solubilized chitosans to propose an approach for the physico-chemical, thermal and mechanical characterizations of this polysaccharide. The polysaccharide used was a 90% deacetylated chitosan having a molecular weight of 98.4 kDa. The flow property of chitosan solutions was evaluated revealing a shear-thinning behavior. The thermal characterization was carried out by studying heat specific capacity, glass transition temperature, and thermal conductivity on chitosan dried specimens (solid state). Their Tg were measured by DSC and confirmed by DMA at 102 and 122°C depending on concentrations of initial chitosan solutions. The mechanical characterization was conducted by analyzing Young modulus, tensile strength, and elongation at break of chitosan specimens. They exhibited a higher elongation at break and a lower tensile strength when made from high concentrated chitosan solution (9% w/v). Differences in mechanical behavior of specimens were explained by differences of crystallinity.