The Research On The Formation And Application Of Carbonaceous Mesophase

The carbon mesophase was prepared by emulsion method and hot polycondensation method respectively. The influence of different temperature, holding time and content ofγ-resin on performance of carbon intermediate researched, and tested the resulted samples by polarization microscope, XRD, BET, etc. High-dense and high-strength carbon materials and active carbon was made using carbon mesophase as starting materials, and explored the process and properties, conclusion as follows:The content of mesophase asphalt increased with hot polycondensation reaction time extension and alkane heterolysis velocity acceleratev in a same given temperature. But on the other hand, the defects turned up in the melt mesophase due to the viscosity of asphalt system increased with the continuous creation of mesophase, which hinder the growth of single ball resulting in the mesophase sphere melt ahead of time. To improve the productivity of mesophase microsphere with excellent performance, not high temperature is necessary, but all kinds of factors such as reactive temperature and time, etc must be considered. The productivity of carbon mesophase was increased with reaction time extension at 430℃and then decreased when the temperature reach 450℃. It is indicated that 430℃is a better temperature for creation of carbon mesophase than 450℃. The large carbon mesophase have cross-shaped distinction stripe, but there are only light spot in small one. Carbon mesophase is a good raw material to prepare active carbon with high-dense and high specific area because of it′s anisotropy and high specific area. The effect of different content ofγ-resin on creation and performance of carbon mesophase. It is deduced that aromatics molecules with side chain and cycloparaffin structure inγ-resin can reduce the viscosity of melt asphalt.The mold pressing samples have a high volume shrinkage in heat treatment which reach 36.19% at 1300℃; The volume density of specimens increased with the temperature, which increased from 1.23 g/cm³ to 1.62 g/cm³ without heat treatment and at 1300℃respectively. The mechanical property of mold pressing carbon mesophase samples improved obviously compare to traditional ones. The flexural strength and compression strength reach 50MPa and 202.92MPa respectively. The dense microstructure was received by heat treatment at 1300℃, and the size of pores in the surface below 5μm, which less than the conventional graphite materials with pore size 90-100μm. The strength of carbon mesophase mold pressing samples was increased with dwell time and then decrease. The best mechanical property will be gained with a 2h dwell time. The specific area of active carbon is different due to different activating agent. The experimental result shows that KOH is better than K₂CO₃ as activating agent. The specific area and porosity of active carbon was increased with the ratio of alkali and carbon and then decreased, and the size of pore was increased with the ratio of alkali and carbon, active temperature and holding time.