Preparation and characterization of a quaternized chitosan

A novel method was developed to obtain N-(2-hydroxy)-propyl-3-trimethylammonium chitosan chloride (HTCC) using glycidyl trimethyl ammonium chloride (GTMAC) and chitosan in a homogeneous system. The factors affecting the degree of substitution (DS) of HTCC, including the amount of perchloric acid, the reaction temperature, and the reaction time, were especially investigated. Under optimal conditions (i.e., with 2.0, 1.9, and 15 g of chitosan, perchloric acid, and GTMAC, respectively), chitosan was pre-reacted with GTMAC at 60 °C, and then the reaction was continued at 80 °C for 8 h. The as-produced HTCC had a DS of 86.9%. Its structure was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Moreover, it had a good solubility in water within a wide pH range. Besides, the composite was formed from HTCC loaded on bentonite surface.