Preparation Of Regenerated Cellulose Microsperes From Sugarcane Bagasse And Their Adsorption To Bromelain

The regenerated cellulose microspheres were prepared by reversed phasesuspensionpolymerizationtechniquewith1-Allyl-3-methylimidazolium chloride([Amim]Cl)as dissolvent and sugarcane baggage cellulose as raw materials.The optimal preparation condition and physio-chemical properties of microspheres were studied.Finally,the adsorption model of the regenerated cellulose microspheres to pineapple proteinase was discussed and the influencing factors were also investigated in the adsorption process.The thermodynamics and dynamics parameters of adsorption process were calculated,and the mechanism of adsorption was preliminarily discussed.1.Cellulose was extracted from the sugarcane bagasse by acid-alkali method,and its purity was 92.23%.[Amim]Cl was prepared by one-step method.The structure of[Amim]Cl was characterized by ¹H NMR,FTIR as well as the viscosity and density analysis.2.The preparing conditions of the cellulose microspheres in the reversed phase suspension polymerization technique were optimized by the signal factor and orthogonal experiments.The results showed that the yield of cellulose microspheres reached 63.2%,and the cellulose microspheres were ivory and round.The microspheres had excellent chemical res istance and thermal stability when they were prepared under the conditions of temperature 80?,mass content of the cellulose 3.5%,the volume of liquid paraffin 200 m L,Span80 5 m L,agitation speed 650r·min^-1.The preparing process did not have chemical reaction,which only the crystalline form of the cellulose was transformed from?to?,and the degree of crystallization decreaseed from 54.58%to 35.21%.3.The effect of adsorption temperature,p H,time,concentrations on the adsorption capacity of bromelain were studied.The experimental results indicated that Freundlich adsorption isotherm equation is adapted to this adsorption process.Thermodynamic parameters were calculated,as?H<40 k J·mol^-1,?G<0,?S>0 indicating that the adsorption was an endothermic,spontaneous and physical adsorption process,which was mainly driven by entropy.And the temperature did not have obvious affect on the adsorption process.Furthermore,the kinetics was found to be best-fited Mc Kay secondary dynamic model and adsorption rate was controlled by liquid film diffus ion.Finally,the calculation values q_e,c were closed to experimental value(R²>0.991),and the maximum absorptive capacity of microspheres was 136.2 mg·g^-1.