Study On Pan Carbon Fiber Precursor Polymerization And Industrialization Design

Carbon fiber is a new material of excellent mechanical properties, with many excellent properties such as high strength and modulus, low density, small coefficient of linear expansion, high thermostability, high fatigue and corrosion resistance, self-lubricating, widely applied in national defense military, industry, recreation and sports equipment, etc. Due to PAN carbon fiber have overwhelming advantage in strength, it accounts for90%in carbon fiber production of the world, and the core technology of PAN carbon fiber is the precursor production, the key of precursor technology lies in the synthesis of acrylonitrile copolymer. Based on the study on acrylonitrile copolymerization reaction in the article, further researching the influence of monomer on polymer thermal properties and structure, and detailedly describe the industrialization design of5000t/a precursor.The main research is as follows:1. Effect of polymerization temperature, monomer concentration and initiator concentration to molecular weight of polymer was discussed in article. The ideal conditions of reaction temperature of58℃and reaction time of2.5h, monomer concentration of25%, initiator concentration of1.5%was discovered.2Through DSC analysis for the thermal performance of terpolymers. It is found that IA decreases the peak temperature(Tp) and the initial temperature(Ti), and it is propitious to cyclization, while MA decreased Tp and increased Ti. Both IA and MA restrict each other and widen the peak together, further decreased the rate of heat release during the PAN precursor pre-oxidation and the possibility of fiber-broken.3. Through infrared ray(IR) analysis for terpolymers. It is found that carbonyl(C=O), hydroxy(-O-H), carbon oxygen bond(C-O) in the terpolymers from ester structure of MA and its partly hydrolyzation. They strengthen the peak at1650～1750cm-1, widen the peak at3500cm-1, overlap and further widen the peaks at909～1333cm-1.4. Stereoregularity of polymer is calculated by Masatomo Minagaw method, showing that MA increases the values of stereoregularity, while IA reduces the values. Meanwhile, stereoregularity increases as the content of MA increases in terpolymers, but the effect is not obvious.5. Based on the experiment study on acrylonitrile polymerization, process route and industrialization design of5000t/a carbon fiber precursor output are described in this paper, and estimate the main process parameters and production technology indexs. Meanwhile, the research route of polymerization unit, stoste preparation unit, spinning unit and solvent recovery unit is described in detail.