Synthesis and characterization of quaternized beta-chitin.

Water-soluble 2'-O-hydroxypropyltrimethylammoniumchitin chloride (2'-O-HTACCt) was prepared directly from beta-chitin and 3-chloro-2-hydroxypropyltrimethylammonium chloride (CTA) in basic medium. The effect of alkali concentration, reaction temperature, reaction time, and dosage of CTA on yield and degree of substitution (DS) of 2'-O-HTACCt were studied. These quaternized chitin derivatives were characterized by FTIR and (1)H NMR spectroscopy, conductometric titration, and elemental analysis methods. Research results indicate that beta-chitin can react directly with CTA to produce a water-soluble 2'-O-HTACCt derivative with a high DS. The optimal preparation conditions were determined to be 35-40 wt% (aq NaOH), 40 degrees C (reaction temperature), 6h (reaction time), and 4 (molar ratio of CTA to beta-chitin unit).