Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/1/2004
Publication Date: 12/5/2004
Citation: Willett, J.L., Jasberg, B.K., Finkenstadt, V.L. 2004 CD-ROM. Effects of process parameters in reactive extrusion of starch [abstract]. BioEnvironmental Polymer Society.
Technical Abstract: Reactive extrusion is a rapid, continuous method for preparing starch-polyacrylamide graft copolymers. Residence times in the extruder are typically between 200 and 400 seconds, depending on conditions. We have investigated the impact of screw configuration and liquid feed configuration on polymerization and properties of the resulting graft copolymers. Using a unit operation approach, screws were constructed with varying number of "reaction zones" or mixing sections and evaluated using two monomer levels and two initiator levels. It was found that screw design had little effect on conversion, graft content, or graft efficiency; monomer and initiator levels were the dominant parameters. In addition, the effects of multiple initiator and monomer injections were evaluated. As the screw configuration, it was found that the amount of initiator and monomer were determining factors, not the number of injection points. These results are consistent with the rapid kinetics of persulfate-initiated acrylamide polymerization, in which the time scale for reaction is on the order of 100-200 seconds.