Compatibility Studies of Chitosan/PEG Blend in 2% Aqueous Acetic Acid Solutions by Ultrasonic Velocity, Refractive Index and Viscosity Techniques, at 303.15 K

Chitosan (CS), a polysaccharide, has many industrial applications and its miscibility studies are most useful. Synthetic polymer, poly (ethylene glycol) (PEG) is a subject of current research interest. Hence, miscibility of CS and PEG in aqueous acetic acid solutions has been studied by ultrasonic velocity, refractive index and viscosity techniques at 303.15 K, over a wide range of compositions ranging from 0-100% of CS in CS/PEG blends. The results of ultrasonic velocity and its derived acoustical parameters such as adiabatic compressibility (β_ad), acoustic impedance (Z), relaxation strength (γ_s) and Rao number (R) have been used to discuss the miscibility/immiscibility of the blend under study. These discussions revealed that the blend is miscible up to 40% of chitosan in the blend and beyond this, the blend is immiscible. Using the viscosity data, the interaction parameters ΔB, μ and α were computed and used to discuss the miscibility/immiscibility nature of this blend. The ultrasonic velocity results are further confirmed by viscosity and refractive index results.