Preparation And Adsorption Properties Of Polyurethane Foam Embedded Modification By Biomass

The presence of organic dyes in industrials wastewater has generated considerable concern in recent years.Compared with other traditional treatment technologies,biosorption technology have been considered to be a potentially valuable technology due to the low cost,easy operation and high efficiency.Carboxymethyl chitosan(CMCTS)and sodium alginate(SA)have broad application prospects in green water purification technology.However,they are easy to agglomerate when used alone,and difficult to separate from wastewater after adsorption.Therefore,Combining the recycling of polyurethane foam and absorption property of biomass,three kinds of noval biomass based polyurethane foams were prepared and their absorption properties were studied.The detail contents are as follows:The carboxymethyl chitosan-modified polyurethane foam(CMCTS-PUF)were prepared by embedding different dosages of CMCTS on polyurethane foam via "prepolymer method".The molecular structure,porosity,surface morphology,thermal and mechanical properties of CMCTS-PUFs were analyzed by FTIR,SEM,EDS,Mercury intrusion porosimetry,TG and other characterization methods.The results showed that when the dosage of CMCTS was 5%,prepared CMCTS-PUF-5 took on good properties.Compared with pure polyurethane foam(PUF),the porosity of CMCTS-PUF-5 increased by 339.4%,the temperature of initial weight loss reduced by 65.1?,the tensile strength increased by 97.0%and the elongation at break reduced by 39.4%.The adsorption results of CMCTS-PUF-5 to MB dye showed that when the temperature was 25?,pH of the solution was not adjusted,the adsorption time was 2 h,the adsorbent dosage was 4 g/L and the initial concentration of dye was 100 mg/L,the removal rate of CMCTS-PUF-5 to MB was 97.1%,which indicated that had a good adsorption effect on MB.The adsorption and recycling experiment results showed that after 6 times of recycling the adsorption efficiency of CMCTS-PUF-5 to MB was still very high which was 89.2%,and the adsorption loss rate was 14.6%.These proved that CMCTS-PUF-5 can be used repeatedly.The results of adsorption mechanism study showed that the adsorption process of CMCTS-PUF-5 to MB followed the pseudo-second-order kinetic equation and Langmuir model,and the process was spontaneous exothermic reaction.The sodium alginate-modified polyurethane foam(SA-PUF)were prepared by embedding different dosages of SA on polyurethane foam via "prepolymer method".The molecular structure,surface morphology,chemical composition,porosity,thermal properties and mechanical properties of SA-PUFs were analyzed by FTIR,SEM,EDS,Mercury intrusion porosimetry,TG and mechanical properties.The results showed that when the dosage of SA was 10%,prepared SA-PUF-10 took on good properties.Compared with PUF,the porosity of SA-PUF-10 increased by 303.0%,the temperature of initial weight loss decreased by 22.1?,the tensile strength increased by 141.2%,and the elongation at break increased by 2.3%.The adsorption results of SA-PUF-10 to MB dye showed that when the temperature was 25?,pH of the solution was not adjusted,the adsorption time was 5 h,the adsorbent dosage was 6 g/L,and the initial concentration of dye was 500 mg/L,the remoal rate of SA-PUF-10 to MB was 90.8%.The adsorption and recycling experiment results showed that after 5 times of recycling the adsorption efficiency of SA-PUF-10 to MB was still greater than 80%.These proved that SA-PUF-10 can be used repeatedly.The results of adsorption mechanism study showed that the adsorption process of SA-PUF-10 to MB exhibited a pseudo-second-order kinetic equation and followed the Langmuir model,and the process was spontaneous exothermic reaction.The carboxymethyl chitosan/sodium alginate-modified polyurethane foam(CMCTS/SA-PUF)were prepared by embedding different mass ratios of CMCTS and SA on polyurethane foam via "prepolymer method".SEM showed that when m(CMCTS):m(SA)was 2:8,the carboxymethyl chitosan/sodium alginate modified polyurethane foam(CMCTS/SA-PUF-28)had good through-hole structure,with many small holes and fold grooves on the wall of the large holes.The cell structure remained intact after MB adsorption.The porosity of CMCTS/SA-PUF-28 was 65.52%measured by mercury intrusion method.Compared with PUF,the temperature of initial weight loss of CMCTS/SA-PUF-28 reduced by 24.9?,the tensile strength increased by 259.8%and the elongation at break reduced by 2.7%.Single factor experiment was conducted to investigate the effect of CMCTS/SA-PUF-28 on the adsorption performance of MB dye under different adsorption conditions.The results showed that when the temperature was 25?,pH of the solution was not adjusted,the adsorption time was 5 h,the adsorbent dosage was 6 g/L,and the initial concentration of dye was 500 mg/L,the removal rate of CMCTS/SA-PUF-28 to MB was 95.3%.The adsorption and recycling experiment results showed that after 6 times of recycling the adsorption efficiency of CMCTS/SA-PUF-28 to MB was still very high which was 81.6%,and the adsorption loss rate was 14.4%.These proved that CMCTS/SA-PUF-28 can be used repeatedly.The results of adsorption mechanism study showed that the adsorption process of CMCTS/SA-PUF-28 to MB followed the pseudo-second-order kinetic equation and exhibits Langmuir model,and the process was spontaneous exothermic reaction.In a word,the prepared CMCTS/SA-PUF-2 takes on better adsorption effect and mechanical properties,as well as its recycling effect is superior,so it have potential application in absorption to dyes.