Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 9/16/2009
Publication Date: 9/16/2009
Citation: Felker, F.C., Fanta, G.F., Salch, J., Shogren, R.L. 2009. Adsorption of Polyethylene from Solution onto Starch Film Surfaces. Meeting Abstract. Cereal Foods World 54: A41.
Technical Abstract: Since starch adsorbs onto polyethylene (PE) surfaces from cooled solutions of jet cooked starch, this study was carried out to determine whether adsorption of PE onto hydrophilic starch film surfaces would also take place if starch films were placed in hot solutions of PE in organic solvents, and the solutions were allowed to cool. Methods such as this for reducing the water sensitivity of starch films through the application of hydrophobic coatings are of interest because of their potential for expanding the range of end-use applications for biodegradable, starch-based products. Starch films were prepared by jet cooking aqueous dispersions of high-amylose starch and then allowing the jet cooked dispersions to air-dry on Teflon surfaces. When the starch films were immersed in 1 % solutions of PE in 1-dodecanol, dodecane and xylene at 120ºC and the solutions were allowed to slowly cool, PE precipitated from the solutions and adsorbed onto the starch film surfaces. FTIR spectroscopy was used to estimate the µg of PE adsorbed per cm2 of starch film. PE was preferentially adsorbed onto the film side that was in contact with the Teflon surface during drying. The amount of PE adsorbed ranged from about 8 to 45 µg/cm2 and depended upon the solvent used and the final temperature of the cooled solution. Scanning Electron Microscopy of starch film surfaces showed discontinuous networks of adsorbed PE on the Teflon side and widely spaced nodules of adsorbed PE on the air side. Nuclear Magnetic Resonance analysis showed that the PE adsorbed onto the starch surface was more linear and/or had a higher molecular weight than the starting PE. Possible reasons for selective adsorption of PE onto the Teflon side of the starch film surface are discussed.