Effect of molecular weight of chitosan with the same degree of deacetylation on the thermal, mechanical, and permeability properties of the prepared membrane

Abstract

Different molecular weight, 90% deacetylated chitosans were obtained by ultrasonic degradation on 90% deacetylated chitosan at 80 °C for various times. Ninety percent deacetylated chitosan was prepared from alkali treatment of chitin that was obtained from red shrimp waste. Number average-, viscosity average- molecular weights were measured by gel permeation chromatography and the viscometric method, respectively. Degree of deacetylation was measured by the titration method. Enthalpy, maximum melting temperature, tensile strength and elongation of the membranes, flow rate of permeates and water are properties measured to elucidate the effect of molecular weight of chitosan on the above thermal, mechanical, and permeation properties, respectively of the prepared membranes. Results show tensile strength, tensile elongation, and enthalpy of the membrane prepared from high molecular weight chitosans were higher than those from low molecular weight. However, the permeability show membranes prepared from high molecular weight chitosans are lower than that from those of low molecular weight.