Study On Preparation And Property Regulation Of Carbon Materials With Bio-based Thermosetting Resin Containing Triazine Ring

Thermosetting resin is widely used in production and life because of its excellent solvent resistance,good thermal stability and mechanical properties.Conventional thermosetting resins are generally synthesized with petrochemical products as main raw materials.Because fossil energy is faced with non-renewable,resource depletion and potential environmental pollution,it has become a research hotspot to develop renewable biomass and bio-based materials to replace petrochemical products to alleviate energy and environmental problems and expand the application of these resins.In view of this,this project uses the biological compound vanillin as raw material to prepare the whole biomass carbon source of triphenol monomer containing triazine ring structure,and to design and synthesize the biological phthalonitrile resin and phenolic resin.The thermosetting resins obtained have high content of miscellaneous elements,good heat resistance and high carbon residue rate.The feasibility of the preparation of porous carbon materials by bio-based thermosetting resins was studied,and the relationship between the preparation process,pore structure of carbon materials,hetero-atomic doping and the macroscopic properties of carbon materials was clarified.TDPH was prepared by a simple one-step reaction between a triazine-containing triphenol monomer THMT derived from biomass carbon and 4-nitrophthalonitrile.At the same time,nitrogen doped graded porous carbon TDPHs was prepared by a two-step process in a tubular furnace with TDPH,urea/zinc chloride compound curing agent and potassium hydroxide as activator.The effects of different curing temperatures on the content of heteroatoms in carbon materials were studied.Tdph350/600（curing temperature 350℃,activation temperature 600℃）has the highest nitrogen content,accounting for 11.91%,and has a high specific surface area of 1523 m²g^-1.At the same time,the electrochemical properties of carbon materials prepared by different curing procedures at 1M H2SO4three-electrode system and CO₂adsorption performance at 273 K and 298 K were studied.It was found that the capacitance of carbon material TDPH450/600 at the curing temperature of450℃was up to 473 F g^-1at the current density of 0.1 A g^-1,and the specific capacitance remained 87%at the current density of 10 A g^-1for 65000 cycles.The adsorption capacity of CO₂reaches 6.8 mmol g^-1at 273 K,and 3.2 mmol g^-1at 298 K.At 298 K,the adsorption/desorption of CO₂by TDPH500/600 could still reach 96.3%of the initial adsorption after 7 cycles.Phenolic resin BPT was prepared by a simple one-step reaction of THMT and 37wt%formaldehyde solution catalyzed by 40%Na OH lye.The presence of homogeneous triazine ring structure makes the T_d5%of BPT resin reach 355℃at 800℃in N₂atmosphere,and the carbon residue rate is 60%.At the same time,BPT resin was carbonized directly in a 500℃tubular furnace without additional nitrogen source.After carbonization,the BPT resin was ground and mixed with potassium hydroxide as activator and activated in the tubular furnace to prepare nitrogen-doped graded porous carbon material BPTs.The effect of activation temperature on nitrogen content in porous carbon was studied.BPTs600 with activation temperature of 600℃has the highest nitrogen content,accounting for 2.84%,and has an ultra-high specific surface area of 3154 m²g^-1.Meanwhile,the CO₂adsorption properties of carbon materials at 273 K and 298 K under different activation temperatures were studied.The adsorption capacity of BPTs800 at 273 K reached 5.3 mmol g^-1.