title: Characteristics of starch-based films with different amylose contents plasticised by 1-ethyl-3-methylimidazolium acetate.
abstract: Starch-based films plasticised by an ionic liquid, 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]), were prepared by a simple compression moulding process, facilitated by the strong plasticisation effect of [Emim][OAc]. The effects of amylose content of starch (regular vs. high-amylose maize) and relative humidity (RH) during ageing of the samples on a range of structural and material characteristics were investigated. Surprisingly, plasticisation by [Emim][OAc] made the effect of amylose content insignificant, contrary to most previous studies when other plasticisers were used. In other words, [Emim][OAc] changed the underlying mechanism responsible for mechanical properties from the entanglement of starch macromolecules (mainly amylose), which has been reported as a main responsible factor previously. The crystallinity of the plasticised starch samples was low and thus was unlikely to have a major contribution to the material characteristics, although the amylose content impacted on the crystalline structure and the mobility of amorphous parts in the samples to some extent. Therefore, RH conditioning and thus the sample water content was the major factor influencing the mechanical properties, glass transition temperature, and electrical conductivity of the starch films. This suggests the potential application of ionic liquid-plasticised starch materials in areas where the control of properties by environmental RH is desired.
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia. Electronic address: fwhsieh@gmail.com.
authors.forename: Fengwei
authors.initials: F
authors.lastname: Xie
authors.affiliation: Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Hartley Teakle Building, St Lucia, Brisbane, QLD 4072, Australia.
authors.forename: Bernadine M
authors.initials: BM
authors.lastname: Flanagan
authors.affiliation: Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Hartley Teakle Building, St Lucia, Brisbane, QLD 4072, Australia.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.affiliation: School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Rowan W
authors.initials: RW
authors.lastname: Truss
authors.affiliation: Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia; School of Chemical Engineering, The University of Queensland, Brisbane, QLD 4072, Australia.
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Halley
authors.affiliation: Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Hartley Teakle Building, St Lucia, Brisbane, QLD 4072, Australia.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Gidley
authors.affiliation: International Institute for Nanocomposites Manufacturing (IINM), WMG, University of Warwick, Coventry CV4 7AL, UK.
authors.forename: Tony
authors.initials: T
authors.lastname: McNally
authors.affiliation: Center for Green Manufacturing and Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.
authors.forename: Julia L
authors.initials: JL
authors.lastname: Shamshina
authors.affiliation: Center for Green Manufacturing and Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.
authors.forename: Robin D
authors.initials: RD
authors.lastname: Rogers
mesh_terms: D000688:Amylose / Q000032:analysis*; D004553:Electric Conductivity; D057927:Hydrophobic and Hydrophilic Interactions; D007093:Imidazoles / Q000737:chemistry*; D055595:Mechanical Phenomena; D010968:Plasticizers / Q000737:chemistry*; D013213:Starch / Q000737:chemistry*; D044366:Transition Temperature
chemical_list: D007093:Imidazoles; D010968:Plasticizers; D013213:Starch; D000688:Amylose; C518739:1-ethyl-3-methylimidazolium
keywords: 1-Ethyl-3-methylimidazolium acetate; 1-Ethyl-3-methylimidazolium acetate (PubChem CID: 11658353); Amylose/amylopectin ratio; Glycerol (PubChem CID: 753); Ionic liquid; Plasticisation; Relative humidity; Starch; Starch (PubChem CID: 24836924); Water (PubChem CID: 962)