Effect of hydrolysis on heat capacity, thermodynamic functions, and the relaxation transition of crab chitin and chitosan

The heat capacity of crab chitin and chitosan is measured in a vacuum adiabatic calorimeter at 10–330 K. The thermodynamic characteristics (enthalpy, entropy, and Gibbs function) are calculated at T → 0 K to 330 K. Differential thermal analysis is used to calculate the relaxation transitions and thermal degradation of chitin and chitosan at 80–600 K. Acid hydrolysis is performed and its effect on the physicochemical properties and thermodynamic functions of chitin and chitosan is studied.