Influence Of Screw Configurations On Grafting Reactive Extrusion In Co-Rotating Twin Screw Extruder

Twin screw extruders as continuous flow reactors for polymers are playing an increasingly important role in reactive extrusion. To optimize screw configurations, the influence of screw configurations of co-rotating twin screw extruder on grafting reactive extrusion had been studied by numerical simulation and experiment research. Six kinds of screw configurations were studied, with different exchangeable elements, including SE30/120, KB30/120, KB150/120, S, TME, NI-MPE.In this paper, the mixing ability of the six kinds of screw elements had been analyzed by numerical simulation using POLYFLOW, and then the simulation results were verified by three relative experiments including the experiment of filling degree, of RTD and of compounding of incompatible polymer, at last the influence of screw configurations on grafting reactive extrusion had been studied by the experiment of MAH melt grafting onto LDPE.The results of numerical analyses show that KB 150/120 has the best mixing ability, the new-type screw element including S, TME and NI-MPE, has a higher distributive mixing ability, and the normal screw element has the worst mixing ability.The results of the experiments show that the screw configurations of intermeshing co-rotating twin screw extruder had a significant effect on the grafting reactive extrusion, especially the mixing ability and the filling degree of the screw element. KB 150/120 had the highest grafting degree, and the novel screw elements could improve the grafting degree rapidly. The screw elements with high distributive and dispersive mixing ability and high filling degree had a higher grafting degree. Experiment results agreed with the simulation results, so developing a novel screw element or selecting the screw configurations for grafting reactive extrusion just need to analyze the characteristic of the screw element.