Investigation Of Elongation Behavior, Pre-Oxidation Process And Mechanism Of Polyacrylonitrile Based Carbon Fibers

In this paper, using high-quality commercial PAN powder (Mw=90000) directlydissolved in DMSO solvent to prepare PAN gel prepared by the PAN precursor samples afterhigh-temperature vacuum drying and pre-oxidation extension. And discusses the preparationof raw silk pre-oxidized PAN fiber-based, high-temperature thermal stability and extend theprocess and mechanism of the process. The results show that when the solubility and gelspinning PAN temperatures is between18g/100ml and30g/100ml between50oC and80oC,suitable for spinning. PAN precursor sample analysis showed that the ratio can be extended,PAN gel concentration28g/100ml, spinning temperature80oC, coagulation bath temperatureof10oC, boiling water drawing rate of1318.8cm/min, the rate of coagulation bath drawing565.2cm/min, as optimal conditions for preparing PAN spinning samples of raw silk. Further,the extension temperature140oC, extension rate25mm/min, the stretching conditions for thepreparation of PAN fiber optimized. Orientation values PAN fiber samples were extendedwith magnification, extending the rate or extend the temperature increases gradually increased,respectively, increases or decreases after the first increase. Pre-oxidized PAN fiber samples,with the pre-oxidation temperature or time increasing its orientation values were significantlydecreased. FTIR analysis revealed different magnification extended temperature had noinfluence on the structure of PAN fibers. With the increase of pre-oxidation temperature ortime of the pre-oxidized PAN fiber corresponds to2242cm-1of the C≡N stretching vibrationpeak decreased gradually, and are gradually increasing peak in1630cm-1C=N stretchingvibration peaks. DSC results showed that the rate increases with the extension, PAN fibersample melting point (Tm) and crystallinity (Xc) were increased to clear the287.5oC/68.7%292.0oC/83.2%. Gradually increases with pre-oxidation temperature or time, PAN pre-oxidized fiber samples were significantly increased melting point but its degree ofcrystallinity was decreased significantly. PAN fiber tensile strength values of samplesincreases with the stretching ratio increased significantly. Of which25mm/min extension rateoptimization extends PAN fiber samples resulting tensile strength of430MPa maximumvalue. In addition, PAN pre-oxidized fiber tensile strength values were pre-oxidation withincreasing temperature or time then decreases. In addition, the optimal conditions for thespinning of PAN precursor resulting sample, and then140oC/25mm/min, respectively, resulting extension8,10,12or15times the pre-oxidized PAN fiber at180oC obtained after6hours pre-oxidized PAN fiber samples, stretch ratio is increased to10times with a tensilestrength value to a maximum value of870MPa.