Characteristics of Chitosan Biopolymer Subjected to Shock Wave Impact

ABSTRACT In the present study, shock wave treated chitosan material properties are investigated. The variation of viscosity, molecular weight, composition, crystallinity, and morphological changes are analyzed. Experiments were carried out in a vertical shock tube maintaining compressor reservoir pressures ( P 4 ) from 100 to 400 kPa, and the shock wave impulses are varied from 50 to 200. To quantify the effects, scanning electron microscopy (SEM), Brookfield viscometer, Fourier transform spectroscopy (FT‐IR), differential scanning calorimetry (DSC) and electric conductivity (EC) measurement diagnostic tools were used. The results demonstrated that shock treated chitosan specimen viscosity significantly reduced by 6%–22%; consequently, its viscosity average molecular weight ( M v ) and degree of polymerization (DP) reduced at an equivalent rate by about 8%–20%. An increase in the intensity of O‐H signals due to the formation of O‐H functional groups by the breaking of glycoside bonds is observed in the FT‐IR spectrum. The enthalpy of melting increased by 19%, and the material conductivity is decreased by 3%–9% as compared to the untreated chitosan material. The variations of the properties emphasize that the material is significantly degraded and partially depolymerized due to the shock wave impact.