Preparation And Properties Of Water-absorbing/Adsorbing Materials Based On Furfural Residue

Furfural residue,an industrial waste rich in cellulose and lignin resources,had not been used reasonably.In this paper,the cellulose and lignin was separated by microwave-assisted extraction from furfural residue in sodium hydroxide solution.The furfural residue cellulose absorbent resin was successfully prepared by the inverse suspension cross-linking grafting method of furfural residue cellulose.The furfural residue lignin/PEI microspheres were successfully prepared by inverse suspension polymerization with furfural residue lignin.The furfural residue cellulose absorbent resin and furfural residue lignin microspheres were characterized by infrared spectrometer(FI-IR),scanning electron microscope(SEM),and X-ray diffractometer(XRD).The water absorption(liquid)properties of the water-absorbing resins were investigated,and the adsorption of the furfural residue lignin/PEI microspheres was discussed for hexavalent chromium from aqueous solution.First,the cellulose and lignin was separated from furfural residue.There were many reports that directly modify the furfural residue.In this topic,we want to separate the effective components in the furfural residue to make its functionality better displayed;The optimum separated conditions were determined through single-factor experiments and response surface design experiments,which the solid-liquid ratio was of 1:20 g/mL,the stir speed of 400 r/min,the lye concentration of 11%,the reaction time of 43min,and the reaction temperature of66?.The characterizations of FT-IR,SEM and XRD affirmed that the furfural residue cellulose showed an irregular spiral as a whole,the furfural residue lignin showed a stick-like structure.The composition of furfural residue cellulose was cellulose of 85.4%,lignin of9.83%and inorganic salt of 4.77%.The relationship between the content of furfural residue cellulose and extraction conditions could be expressed with the secondary polynomial regression equation as Y=84.25+1.59A+0.94B+2.43C-0.22AB+0.61AC+1.3BC-3.75A~2-3.21B~2-2.36C~2(Where A was the alkali concentration(%),B was the time(min)and C was the temperature(?)).The composition of furfural residue lignin was lignin of 58.3%,cellulose of24.7%and inorganic salt of 17.0%)Second,the furfural residue cellulose/AA/AM water-absorbent resin was prepared.Many scholars have used biomass resources as raw materials to prepare water-absorbent resins.In this topic,we want to use biomass waste resources-furfural residue as raw materials,turning waste into treasure;The optimum preparation conditions were obtained through single-factor experiments and orthogonal experiments,which the composite monomers(mAA:mAM=2:1)dosage was of 9.00g,the initiators dosage of 2.20g,the crosslinkers dosage of 0.07g,and the reaction temperature was of 62?,the AA neutralization was of 65%,the oil-water volume ratio was of 1.3:1.The water absorption(liquid)ratios of the prepared water-absorbing resin to deionized water,tap water and artificial urine were 179g/g,40.5g/g,and 18.3g/g,respectively.The FT-IR,SEM and XRD characterizations indicated that the morphology of the water-absorbent resin grafted with AA and AM was not significantly different from that of furfural residue cellulose,but an irregular shape,and the crystal form did not change significantly.Third,the furfural residue lignin/PEI microspheres were prepared.At present,the research technology of hexavalent chromium adsorption is relatively mature.In this subject,we want to prepare a microsphere material with a large specific surface area to improve the adsorption capacity.The optimum preparation conditions for furfural residue lignin/PEI microspheres were obtained through single-factor experiments and orthogonal design experiments,which the lignin dosage was of 0.60g,the PEI dosage of 2.25g,the dosage of2.25m L,the SDBS dosage of 0.075g,the temperature was of 56?,and the oil-water volume ratio was of 4.5:1.The structure and morphology of microspheres was characterized vio FT-IR,SEM,XRD and laser particle size analyzer.The surface of the microspheres had a small number of holes and fibrous structures.The average particle size was of 135?m,the uniformity was of 0.290,and the particle size distribution was more uniform.The morphology of lignin changed significantly from stick-like to spherical,and the crystallinity was also greatly reduced.Finally,The adsorption properties of furfural residue lignin/PEI microspheres were discussed.The optimum conditions for the adsorption of Cr(VI)from aqueous solution were obtained through optimizing the experimental conditions.When the initial concentration of Cr(VI)was of 140 mg/L,the pH value of 5,the adsorbent dosage of 20mg,the adsorption time of 120min and the adsorption temperature of 55?,the maximum adsorption capacity was of 263mg/g.The adsorption model of furfural residue lignin/PEI microspheres was discovered that the adsorption behavior of microspheres to Cr(VI)was more consistent with Langmuir adsorption model,and the two-stage kinetic model was more suitable to describe the adsorption behavior of microspheres.The adsorption of Cr(VI)by microspheres was an endothermic chemisorption process.