Synthesis and Characterization of N-(carboxy-methylthioureido)-Chitosan and its Dispersion Capability

Abstract

Water-soluble N-carboxymethylthioureidochitosan (CMTC) was synthesized by the reaction between chitosan (CTS) and ammonium thiocyanate and chloroacetic acid in a hydrochloric acid aqueous solution. The modified product was confirmed by Fourier transform infrared (FTIR) spectrometry, X-ray diffractometry (XRD) and thermal analysis. The results showed that new functional groups had been linked to amino groups of CTS molecules, and the product was more amorphous than CTS. The dispersion stability of CMTC was examined with a sedimentation test of 1 wt.% kaolin suspension in test tubes, under different concentrations and different pH. The results indicated that CMTC may be applicable for use as a novel stabilizer in neutral solution in which the concentration of CMTC is 0.5% or 1%.