EFFECT OF PRESSURE ON ELASTIC PROPERTIES OF CHITOSAN

The work focused on studying the elastic properties of chitosan composite system. The samples were prepared in form of compressed pellets. The structure and elemental analysis of chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTIR). The FTIR spectra have been recorded in the spectral range from 280-4000cm -1 . The velocity of sound of chitosan is obtained by the ultrasonic pulse-echo measurements, at room temperature. Both longitudinal and transverse velocities of chitosan are pressure dependence. From the value of density, longitudinal and shear ultrasonic velocity, the value of longitudinal modulus (L), shear modulus (G), bulk modulus (K), Young modulus (E) and Poisson ratio (σ) were calculated. The sound velocity increases as the density and pressure increase. The elastic modulus and Poisson’ ratio show increasing trend as the pressure of sample increases. The elastic modulus increases due to the compactness of the pressed sample. As the pressure and density increase, the atoms in chitosan became more compact thus the ultrasonic waves are dispersed between the atoms resulting in more propagation of wave.