Design And Preparation Of Interpenetrating Network Strong Basic Resin And Its Decolorization Performance Toward Xylose Mother Liquor

Xylose,a representative functional sugar,has been widely applied in food,light industry and other fields.The acid hydrolysis of hemicellulose produces pigment substances expcept for reducing monosaccharide,and the caramelization and Maillard reactions occur during xylose mother liquor concentrating,both of them result in the production of a large number of pigments.In this way,it is difficult to fully recover the reducing sugar components in xylose mother liquor and only sold at a low price,resulting in a waste of natural resources.The structure of the existing ion exchange resin is relatively single,which has the disadvantages of poor selectivity and high sugar loss rate for xylose mother liquor.Therefore,exploring and preparing a new ion exchange resin with good decolorization performance and strong selectivity in order to obtain high-quality xylose liquor is of great practical significance.This paper aimed to design and prepare an interpenetrating network resin by interpenetrating network(IPNs)technology,and then applied the as-prepared resin to the decolorization and purification of xylose mother liquor.The adsorption process and mechanism of pigment substances on the resin were investigated through static and dynamic adsorption experiments.It provides a new idea for decolorizing and refining xylose mother liquor by ion exchange resin.The main work and conclusions are as follows:Firstly,the types and contents of reducing sugar,the composition and physicochemical properties of pigment in xylose mother liquor were characterized by various analytical methods.The results showed that the total content of reducing sugar in xylose mother liquor was 635.51 mg/m L,including 508.01 mg/m L xylose,56.28 mg/m L glucose and 71.22 mg/m L arabinose.The pigments in xylose mother liquor mainly include furfural organic matter,phenolic organic matter,caramel pigment,Maillard pigment.Seven phenolic organic compounds were identified in the xylose solution.The molecular weight of Maillard reaction products can be divided into three distribution bands,about 8964 Da,772 DA and 445 Da,accounting for 2.91%,32.47% and 64.62% respectively.Secondly,IPNs technology was successfully used to prepare the interpenetrating network resin PDVB/PMATAM,which was analyzed by XRD,SEM,TGA and other characterization methods,and its decolorization performance of xylose mother liquor was preliminarily investigated.The results show that the resin has typical amorphous structure,loose and porous surface and good thermal stability;PDVB/PMATAM resin has excellent performance in the evaluation indexes such as decolorization rate of xylose mother liquor and loss rate of reducing sugar,and the decolorization effect is outstanding compared with the commercial adsorbent;Taking ferulic acid,furfural and melanin like intermediates as examples,the interaction energy between PDVB/PMATAM resin and pigment was obtained by quantum chemical calculation.Thirdly,the effects of different synthesis conditions on the BET specific surface area,pore structure and adsorption properties of the resin were explored,and the adsorption mechanism of the resin was explored by static adsorption experiment.The results showed that the decolorization rate of xylose mother liquor was 94.5% and the loss rate of reducing sugar was 4.1% under the optimum conditions;The adsorption kinetic curve of pigment on resin conforms to the pseudo-second-order model,and the equilibrium adsorption process was more consistent with Langmuir model;And the heterogeneity of resin surface active adsorption sites was verified by do’s model;In addition,the resin showed good regeneration and reusability.Finally,the adsorption and desorption process process of the PDVB/PMATAM-9 resin in dynamic form was explored.The results showed that the adsorption isotherms of pigment and sugar components obtained by the step-method were well fitted with Henry model;The predicted curves of ED model were in good agreement with the penetration curves of pigment and sugar components obtained under different operating parameters;When the desorber is a mixed solution of 2% Na OH and 20% ethanol and the flow rate is 1 m L/min,the elution effect of the resin column is better.