| The phenolic resin is widely used in processing industry because of its water resistance,heat resistance,weather resistance and good chemical stability.However,phenol and formaldehyde were non-renewable petroleum chemical products,and the shortage of non-renewable energy sources have caused energy crisis and environmental pollution,which forced people to look for alternatives to petrochemicals.Biomass contains a lot of hemicellulose and lignin.The hydrolysis of hemicellulose contains aldehyde groups and lignin contains phenolic hydroxyl,which aldehyde groups and phenolic hydroxyl could be substituted for formaldehyde and phenol to synthesize lignin-phenol-furfural-formaldehyde?LPFF?resin.This paper mainly uses corn cob as raw material,and furfural was prepared by catalytic hydrolysis of hemicellulose.Lignin,furfural,phenol and formaldehyde were used as raw materials,LPFF resins were synthesized by copolymerization.LPFF resins were prepared by curing,then,carbonization and activation of LPFF resins.The effects of synthesis conditions on the properties of LPFF resin adhesives and the electrochemical properties of LPFF resin carbon were studied.The results obtained were as follows:1.The different dosages of furfural and lignin have important influence on the bonding strength of LPFF resins.?1?Lignin was less than 50%of phenol,and the bonding strength of lignin phenolic resin?LPF?was greater than that of pure phenol formaldehyde resin?PF??1.22MPa?,which indicated that the substitution of lignin for phenol could improve the bonding strength of LPF.?2?The experiment of different substitution rates of lignin to phenol in each group showed that with the increase of the ratio of furfural to formaldehyde,the bonding strength of LPF increased,and the best when each group reached 15%substitution rate.It indicated that furfural had better cross-linking polymerization than formaldehyde and could be used as a cross linker in the process of synthetic adhesive.?3?When the substitution rate of lignin to phenol was 60%and the substitution rate of furfural to formaldehyde was 20%,the bonding strength of LPFF was 1.41MPa,which was higher than that of PF,and the total substitution rate of biomass based chemicals could reach 80%.?4?When the substitution rate of lignin to phenol was 40%,and the substitution rate of furfural to formaldehyde was 15%,the comprehensive performance of LPFF was the best and the bonding strength was 1.97 MPa.2.Activated carbon were prepared from LPFF resin by chemical activation.By controlling the substitution rate of furfural to formaldehyde,the pore size and distribution could be regulated,and achieved the best specific capacitance.When the replacement of furfural to formaldehyde was 5%,the specific capacitance was 309.12F/g,and showed a good cycling stability with the capacitance retention rate reached97.70%over 10000 cycles.3.A one-step method was used to add excess NaOH in the synthesis process of resin and as activator in the subsequent activation process.In the activation process,adding a little KOH?NaOH:KOH=3:1?.LPFFC had a higher specific capacitance was277.94 F g-1.The method reduced the preparation process of activated carbon and also protected the environment.4.Lignin-phenol-furfural-formaldehyde resin carbon?LPFFC?was the electrode material of lithium ion battery.The electrochemical test results show that the replacement of furfural to formaldehyde was 5%,the first discharge capacity of 1132mA h g-1 at the current density of 100 m A g-1,a reversible capacity of 327 mA h g-1after 100 cycles,and the rate capability was also good. |
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