Influence Of Molecular Structure Polycyclic Aromatic Hydrocarbons On The Carbonized Product

Here we use polycyclic aromatic hydrocarbons (PAHs) from coal tar pitch as raw material, adopting thermal polymerization, alkylation and liquid phase carbonization process to modify the PAHs. The purpose is to study the influence of structure for polycyclic aromatic hydrocarbons to its carbonized product form, structure and performance. Main subjects content as follows:using prene and anthracene as raw material separately for thermal polymerization to get the reaction product, then combine the pyrene and anthracesne polymerization product with mesocarbon micarobeads (MCMB), selecting azodiisobutyronitrile (AIBN) and dodecene as catalyst, mixing the raw material and catalyst with certain proportion to get alkylation product and make the characterization analysis. Then we do carbonization for the PAHs, by changing the raw materials of them, we can study the influence of different ingredients with different modified process for the carbonized products’ structure and performance. Here we also adopt nuclear magnetic resonance (NMR), mass spectrometry, infrared microscopic to analyze polycyclic aromatic hydrocarbons with different structure of the compounds in the optical microscopic morphology, as for the carbonized product, we do carbide crystal structure and morphology characteristics analysis. We also investigate the relationship between the molecular structure of raw material and carbide product structure, and the mechanism of polycyclic aromatic hydrocarbons in heat treatment of graphite transition, in order to understand the effect of various components in mesophase pitch to carbide product structure, at the same time, making sound foundation for the preparation of high quality mesophase pitch and carbon fiber in future.1、We study two kinds of PAHs pyrene and anthracene separately, without adding any catalyst, we do thermal polymerization for them directly and adopt solvent separation to get polymerized product with different structure, also by characterization testing to determine their composition, molecular weight, substitution method and group to accurately predict their chemical structure separately. The results show that the insoluble and infused polycyclic aromatic hydrocarbons in direct thermal polymerization process can improve the solubility of crude material.2、Combine the pyrene polymerization product, anthracene polymerization product and MCMB toluene ball respectively with azodiisobutyronitrile and dodecene, mixing in certain proportion for alkylation process under 400 ℃, to get the PAH derivatives with alkyl side chain. Also by testing, we can know for PAHs derivatives with different molecular weight and alkyl side chain, the original insoluble and infused polycyclic aromatic hydrocarbons can effectively change its solubility by dealing with alkylation, to prepare good soluble polycyclic aromatic hydrocarbons derivatives with alkyl side chain.3、Dealing polycyclic aromatic hydrocarbons of anthracene and pyrene derivatives in liquid phase carbonization experiment, by using heat polarization microscope to observe their mesophase formation process respectively. It was found that the existence of the alkyl side chain is conducive to the formation of the mesophase structure, while the big size of the core structure for polycyclic aromatic hydrocarbons and enough alkyl side chain is also conducive to the improvement of the mesophase liquid crystal structure.4、Using polycyclic aromatic hydrocarbons and its derivatives as raw material, doing carbonized experiments under the 1000℃and study its products, through the characterization test we found that the different structure of polycyclic aromatic hydrocarbons will have different effects on the structure and performance of carbide products. Polycyclic aromatic hydrocarbons, which can form the flow of mesophase structure have little impact on the carbide graphite crystallite structure; the existence of alkyl side chain can reduce the carbide layer spacing, but affect limitedly for the unit cell of graphite crystallite size and the increase of the macro ordered structures; the larger length of polycyclic aromatic hydrocarbons and the bigger of molecular weight, its carbonized product of graphite crystallite structure cell size is larger; as for the polycyclic aromatic hydrocarbons in length of diameter is quite small, polycyclic aromatic hydrocarbons ring number is greater than 8, the ring number of microcrystalline structure has little effect for carbide products; preparing samples of carbonization PAHs under no stress state, there are lots of disordered structure in carbide.5、Combing insoluble pyrene polymerization alkylation products and insoluble anthracene polymerization alkylation products, with nano calcium carbonate (hydrophilic/lipophilic) respectively, then mixing in coking furnace uniformly, rapidly heats up to 800℃ under pure nitrogen environment to make preparation of nano lamellar structure of different forms, with thickness around 2 to 4 nm. It was found that the raw material structure and adding species of calcium carbonate have obvious influence on the product form.