Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 8/15/2006
Publication Date: 9/15/2006
Citation: Willett, J.L., Finkenstadt, V.L. 2006. PRODUCTION OF STARCH GRAFT COPOLYMERS USING REACTIVE EXTRUSION. Meeting Abstract. xx.
Interpretive Summary: Starch is a low-cost, renewable agricultural product from corn, wheat, and potatoes. It provides a platform for producing biobased functional polymers, such as starch graft copolymers (SGPs), which combine the properties of starch with synthetic polymers. We have prepared SGPs with a combination of acrylamide (AAm) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) using a continuous extrusion process. These SGPs, which are 75% by weight starch, can hold up to 200 times their weight in water. The water absorbent properties depend on the relative amounts of AAm and AMPS in the SGP, and are directly proportional to AMPS content. These results demonstrate the potential of producing functional starch-based superabsorbents by extrusion, which has benefits compared to the conventional batch process. These starch-based superabsorbents offer new market opportunities for starch, and improve the economic competitiveness of U.S. agriculture.
Technical Abstract: There is considerable interest in the use of starch graft copolymers for applications as hydrogels, controlled release, and superabsorbents which involve contact with water. Typical production methods use batch processess at relatively low solids content, which produce large amounts of ungrafted homopolymer, low graft efficiencies, and batch-to-batch variability. Reactive extrusion is a continuous process which can produce starch graft copolymers at solids contents of 50% or higher with high conversions and grafting efficiencies. Graft copolymer properties such as molecular weight and graft frequency can be controlled through appropriate selection of formulation and process parameters. Examples including starch-graft-polyacrylamide and terpolymers of starch, acrylamide, and 2-acrylamido-2-methyl propane sulfonic acid will be discussed.