Synthesis Of Pan-based Carbon Fiber Precursor And Performance Characterization

This article selects acrylonitrile (AN) as the first monomer, methyl acrylate (MA) as the comonomer, then synthesized the acrylonitrile copolymer through free-radical solution copolymerization using azodiisobutyronitrile as initiator in DMSO. We analyzed the reaction system through controlling the monomer concentration, initiator, reaction temperature, reaction time. The result indicated that, increasing reaction time and initiator concentration, raising reaction temperature, all may enhance conversion of the polymerization system, but can reduce the molecular weight of the copolymer, broaden molecular weight distribution.We have analyzed and signified the structure and performance of the acrylonitrile copolymer through infrared spectrum (FTIR), nuclear magnetic resonance (¹H-NMR), X -ray diffraction, etc. we also have attributed the thermal properties used DSC and TGA. We find along with the MA content increase, the exothermic peak is moved into the high-temperature. And the increase with monomer concentration, the glass transition temperature presents the obvious reducing trend. When the monomer proportion is 80:20, there seemed to be an unidentified glass transition temperature. There is not obvious weightlessness from room temperature to 270℃, but we can divide the whole weightless course into three stages since 270℃. Appeared the different characteristic peak in the different wave numbers, This has fully proved MA has copolymerized reacting with AN, structural unit MA exists in the results, Several copolymer samples have peak in22.18 , simultaneously ratio of this position peak intensity with 16.78°increases along with the MA proportion. Peak which appeared in 8=3.34ppm and 8=2.5ppm is a characteristic peak of H in water and DMSO. The H proportion should be 2:1 in -CH₂- and -CH₂CH, but this ratio existence uncertainty in our copolymerization. Through the calculating of he peak aera, the content of MA is basically identical with throwing the material amount to compare with actually. So we can control the proportions of AN and MA in copolymer by controlling single matching.