Studies On Synthesis, Characterization And Adsorption Performance Of Crosslinked Cassava Starch Microspheres

In this paper,we Cassava starch was taken as raw material, Crosslinked cassava starch microspheres were synthesized by the way of reversed-phase suspension polymerization, and we conduct the research program of CCSM which included the synthesis technology, characterization, physical and chemical properties and adsorption performance.Using the productivity and diameter of CCSM as response variable, the concentration of cassava starch, volume ratio of oil phase to water phase, quantity of linker, quantity of emulsifier, polymerization time, polymerization temperature, stirring rate were by single factor design experiment. The optimum polymerization conditions were decided by experiments as follows:3000r/min of stirring rate,2.4 g of cassava starch, the water-oil phase volume ratio of 1:4,0.5g of MBA,0.6 g of K2S2O8, polymerization temperature at 65℃, polymerization time for 2 h and stirring rate of 1000r/min. Cassava starch microspheres have high productivity by this synthesis technology, and CCSM are sherical particulates with rough surface and small particle diameter.Using Scanning electron microscope(SEM), Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction and Thermogravimetric analyzer, we have carried out the detailed analysis research on the apparent, structure and performance of Crosslinked Cassava starch microspheres. The results showed:CCSM were a neat Spherical and rough surface polymer, and there was no obvious adhesion phenomenon between them. FTIR:Obvious telescopic vibration absorption peaks appeared in 3400cm-1,1651 cm-1 and 1536 cm-1, and crosslinking groups constantly replaced the starch molecular hydrogen bond. X-ray diffraction:More peaks of cassava starch microspheres basically disappeared near multiple angles. There were no obvious diffraction peak of characteristics, and crystallinity obviously decreased, presented amorphous curve feature of the diffraction peak. Thermal analysis: Thermal decomposition of cassava starch and microsphere have already experienced three stages, with its thermo-decomposing temperature rising, the rate of weightlessness in microsphere was more moderate than in cassava starch, then the thermal stability of CCSM has been greatly improved. Adsorption performance of CCSM for Fe3+ was investigated. The product after adsorption was characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD)and Thermogravimetric analyzer, then we discussed the mechanism of adsorption. The adsorption results showed that the CCSM have better adsorption property towards Fe3+ when pH of solution is 4.5, and reach adsorption balance in two hours.The adsorption behavior of CCSM towards Fe3+ is adapted to isothermal equation of Freundlich in the experimental conditions. The Fe3+ was adsorbed by means of physical adsorption and weakly complexation.