Submitted to: Society of Plastics Engineers Proceedings
Publication Type: Proceedings
Publication Acceptance Date: January 9, 2008
Publication Date: N/A
Technical Abstract: Starch, a low-cost, annually renewable resource, is naturally hydrophilic and its properties change with relative humidity. Starch’s hygroscopic nature can be used to develop materials which change shape or volume in response to environmental changes (e.g. humidity). For example, starch-based graft copolymers have been produced using reactive extrusion for potential superabsorbent and hydrogel applications. Besides absorbing large quantities of water, some of these copolymers display large volume changes in aqueous alcohol depending on solvent quality. Other examples include starch-poly(methyl acrylate) graft copolymer films which shrink at high humidities. Various levels of shrinkage can be triggered in response to changes in relative humidity.