Kinetics Study and Product Characteristics of Depolymerization of ?-Carrageenan in the Presence Hydrogen Peroxide

Low molecular weight (LMW) of ?-carrageenan has large applications in pharmaceutical and biomedical function. LMW of ?-carrageenan can be effectively prepared by H2O2 oxidation. This study aims to determine the effect of process variables such as reaction time, temperature, solution pH and H2O2 concentration on the rate of depolymerization of-carrageenan. The functional and morphological properties of LMW of ?-carrageenan was characterized by Fourier transform infrared spectroscopy (FT-IR), SEM and XRD of ?-carrageenan effectively degraded using H2O2 and the maximum degradation can be obtained under the reaction condition of 50oC, 1.5% H2O2 and pH 10 in 30 minutes reaction times. At these reaction conditions, the degradation rates of ?-carrageenan achieved 76.41% and the kinetic value was 2.46x10-4. The activation energy of plot Arrhenius law of temperature dependence of kinetics rate constant is 41.97 kJ. mol-1. The analysis of functional groups using FT-IR showed that there are no significant changes of structure of degraded ?-carrageenan under H2O2 treatment. The results of SEM analysis show that after the degradation process the surface becomes rougher and more porous. The results of the crystallinity test of carrageenan after XRD degradation showed that it became more amorphous.