Abstract

LAREZ VELASQUEZ, Cristóbal  and  ZAMBRANO DIAZ, Leonardo. CHITOSAN DEPOLYMERISATION BY POTASSIUM PERIODATE. Rev. LatinAm. Metal. Mater. [online]. 2011, vol.31, n.2, pp.195-202. ISSN 0255-6952.

Chitosan degradation with potassium periodate was studied in well controlled aqueous conditions (acetic acid (0.3M)/sodium acetate (0,2M) buffer and 25ºC) in order to establish the preferential process occurring during the initial stages of the reaction. Depolymerization of the polysaccharide through of the hydrolysis of glucosidic bonds seen to be the principal reaction due to FTIR spectra of the reacted samples did not show appreciable changes but their viscosity and gpc traces indicate a pronounced molecular weight decreasing. Additionally, a kinetic study was also carried out - employing viscosimetric data (Sano´s equation) and the initial velocity approach - giving as result the following equation for the depolymerization apparent velocity: v = 1.878[chitosan]^1,40[IO4 -]^0,65

Keywords : Depolymerization; chitosan; periodate oxidation; hydrolysis; viscosimetry; Sano’s equation.