Abstract
Transformation of chitosan in conc. H2SO4 was investigated. Neither reaction temperature (0, 10, and 30°) nor time (1-10 hr) affected the degree of sulfation of chitosan, but it was markedly influenced by temperature of the ether used to separate sulfated products. It was proved that depolymerization of chitosan, which had been observed to be extremely stable to conc. H2SO4, was influenced by the remaining N-acetyl content in chitosan. As expected, chitosan was greatly depolymerized by treatment with hydrated conc. H2SO4 (80 and 90% of sulfuric acid by weight), and sulfated in a lesser extent than that of conc. H2SO4.
A hydrolysis constant, K1 7.0×10-2 min-1, of the acid-labile sulfate in sulfated chitosan indicated a reliable formation of the N-sulfate bound to the amino group in sulfated chitosan.
