The Control And The Study Of Polymerization In Du Pont PAN Dry-spinning Process

This article mainly studies the reaction control of dry-spinning PAN method in the small scale experiment and the industrial scale test.The small scale experiment showed that in the industrialized experiment. The slurry should be kept on 20 hours.The excessive SO2 that reacted with NaOH is used as activator. By calculation, parameter value in activating tower was determined. By experiment, if the pH was kept at 4.2-5, free acid concentration of polymers can be kept at 1.5-3.0mmol/kg. If the pH of the slurry was controlled at 4.6±0.1, the free acid concentration of polymers can be kept at 1.8-2mmol/kg. The industrial production will be more stable and have higher performance. The study showed that 2mg/l Fe2+ concentration was more suitable for PAN fiber production. If the control of Fe2+ was fail and the Fe2+ concentration increased, the viscosity of polymer, the glass-transition temperature and the mechanical properties all decreased. It impacted on the spinnability of the polymer. When the polymerization rate in reactor increased and the volume of reactor was kept constant, the polymerization rate increased to 110 t/day from 95 t/day. The operation period of polymerization reactor was 20 days.The reaction time reduced from 38.69 min to 35.3min.Under such condition, the concentration of the reaction material increased. The viscosity of polymers became higher and the macromolecular weight increased. The performance of polymers changed. The production of PAN fibers was also influenced.