Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 10/18/2015
Publication Date: 10/21/2015
Citation: Felker, F.C., Finkenstadt, V.L., Selling, G.W., Fanta, G.F., Hornback, K.J. 2015. Properties of amylose-oleic acid inclusion complexes from corn starch grafted with poly(methyl acrylate) [abstract]. American Association of Cereal Chemists.
Technical Abstract: Corn starch granules have been previously investigated as fillers in polymers. In this study, much smaller particles in the form of spherulites produced by steam jet-cooking high-amylose corn starch and oleic acid to form amylose inclusion complexes were graft polymerized with methyl acrylate, both before and after removal of un-complexed amylopectin. For comparison, granular high-amylose corn starch was graft polymerized in a similar manner. The amount of grafted and ungrafted poly(methyl acrylate) were similar for all of the starch-graft-poly(methyl acrylate) copolymers. Starch graft copolymers were processed by extrusion, and tensile properties of the extrudates were determined. Although extruded ribbons with similar tensile strengths were obtained from the three starch-PMA graft copolymers, higher values for % elongation were obtained from the spherulite-containing copolymers. Analyses of the graft copolymers indicated that the molecular weights of grafted and ungrafted PMA were similar for the three copolymers. Interaction of the grafted starch material and the homopolymer in extrudates as revealed by iodine staining and scanning electron microscopy supported the conclusion that the higher % elongation values may be attributable to the smaller size of the amylose-oleic acid spherulites compared with unmodified starch granules.