Reactive Extrusion of Polypropylene Using the Peroxide Initiated Vis-Breaking Reaction

摘要

Reactive extrusion has not yet been controlled using physically motivated models. This paper uses residence distribution analyses to characterize the material flow through a corotating twin-screw extruder. Additionally the signals have been deconvoluted to kinematically characterize the flow in the different regions of the extruder. Studies of step changes have shown that the steady state value of extrudate viscosity is dependent on the peroxide, volume mixing, and on the residence time from the specific throughput of the extruder. This data has also been shown to provide plant models of the peroxide initiated degradation reaction using ARX determination techniques. These models agree with work by Gao et al., which illustrates that the extruder can be looked at like a series of stirred tanks with time delays. Although a specific example of vis-breaking of polypropylene is studied, the techniques are general and an be expanded to other reactive systems. Future directions and proposed research for the control of reactive extrusion are also discussed.