Synthesis And Adsorption Properties Of Anion Magnetic-starch Microspheres(AMSMs)

Starch is a crude high polymer material with much reserve, therefore synthesis and adsorption modification of starch was studied as an important field. Compared with others polymer microspheres, CSM are biocompatibility, degradation and low cost. Therefore research of anion magnetic-starch microspheres (AMSMs), which has high adsorption capacity for trace heavy metal ions, the efficient capture, rapid directional separation of anionic magnetic starch microspheres, is attached importance to many groups.In this thesis, MBAA graft copolymerization of starch microspheres synthesis was first studied with the microwave. Formula and technology of microspheres synthesis are considered. The results showed that the optimal conditions of the orthogonal test of the crosslinked starch microspheres (CSM) were as follow:the dosage of the MBAA, initiator and emulsifier are0.2g,0.1g and0.2g, the volume ratio between the cyclohexane and water is4:1and the concentration of the starch is20%. From range we can see that main factors affecting adsorption properties of microspheres are amount of crosslinking agent and initiator, while starch concentration on the adsorption properties of the starch microspheres affect small. Through single factor optimization experiments, the optimal conditions of the preparation of the CSM were as follow:the dosage of the MBAA is0.3g/g, the concentration of the starch is23%, the volume ratio between the cyclohexane and water is3.5:1, the dosage of initiator is0.05g/g, the molar ratios between the K2S2O8and NaHSO3is2:1. The testing of SEM, inverted microscope showed that the morphology of the crosslinked starch microspheres rounded, the surface roughness, and can be synthesized the average particle size of2um-5um of the microspheres by changing the formula and technology. IR spectra shows that the MBAA and starch cross-linking reaction. XRD analysis showed that the degrees of crystalline of the crosslinked starch microspheres lower. Followed by the rule of law to prepare starch microspheres with the microwave on the basis of corn starch and magnetic powder as raw materials, study the starch concentration, initiator concentration, crosslinker concentration, the oil-water ratio (V/V) and Fe3O4on the magnetic properties of starch the swelling degree and the adsorption properties, the best conditions for the synthesis of magnetic starch microspheres obtained by microwave method is as follow:the initiator concentration0.15g/g, the concentration of the starch20%, the volume ratio between the cyclohexane and water is4:1. Crosslinking agent concentration of0.4g/g, Fe3O40.4g/g. Through single factor optimization experiments, the optimal conditions of the preparation of the NMSMs were as follow:the concentration of the starch is18%, the dosage of the MBAA is0.4g/g, Fe3O40.4g/g, the volume ratio between the cyclohexane and water is2.5:1. IR spectra shows that the MBAA and starch cross-linking reaction. XRD analysis showed that Fe3O4crystal particles contained in the product,on the basis of magnetic starch microspheres prepared with the microwave, legal system of Cu2+adsorption performance evaluation, immersion graft orthophosphate foundation group, explore the adsorption properties of AMSMs under the influence of the soaking time, soaking temperature, orthophosphate concentration, and alkalinitythe. The optimal synthesis conditions obtained as follow:soaking time20h, soaking temperature50℃, orthophosphate mass concentration of1.5g/g, alkalinity0.4g/g. Under the optimal conditions, the synthesis AMSMs saturation adsorption capacity of Cu2+is322.68mg/g while of Pb2+is450.97mg/g. AMSMs IR spectrum shows the starch and orthophosphate grafted through resterification reaction to produce a starch phosphate which has good adsorption properties. XRD shows that AMSMs successfully grafted onto the orthophosphate.