Volume 89, Issue 12, Pages 3323-3328
Received: 8 October 2002; Accepted: 17 December 2002
Published Online: 1 Jul 2003
George F. Fanta (a) (*) , Frederick C. Felker (b), John H. Salch (a)
(a) Plant Polymer Research, National Center for Agricultural Utilization Research, United States Department of Agriculture, 1815 North University Street, Peoria, Illinois 61604-3999
(b) Cereal Products and Food Science Research, National Center for Agricultural Utilization Research, United States Department of Agriculture, 1815 North University Street, Peoria, Illinois 61604-3999
(*)Correspondence to George F. Fanta, Plant Polymer Research,
(**)Mention of a trademark, proprietary product, or vendor does not constitute a guarantee or warranty of the product by the U.S. Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.
Keywords: starch • polyethylene • acrylonitrile • polyacrylonitrile • graft copolymer
Starch-coated polyethylene (PE) films were prepared by immersing PE in a hot, jet cooked solution of starch. They were allowed to react with acrylonitrile (AN) in the presence of ceric ammonium nitrate initiator, and the graft polymerization that occurred produced starch-g-polyacrylonitrile (PAN) coatings that contained about 25 wt % grafted PAN. The starch-g-PAN coatings tightly adhered to the PE film surfaces. When grafted starch coatings were wetted with water and the surfaces vigorously rubbed, less than 20% of the coating was removed. The fact that PAN-grafted coatings were not removed with boiling water provided further evidence for their strong adherence. When starch was removed from the coating by acid hydrolysis, the residual grafted PAN still remained adsorbed on the PE surface. Because the grafted coating was completely removed by treatment with refluxing 0.7N sodium hydroxide, there is apparently no chemical bonding between starch-g-PAN and PE. The dimensional changes associated with the evaporation of water from these PAN-grafted coatings caused the films to curl during drying. Because the final shape of these coated films depends upon the presence or absence of water in the surrounding environment, these films may be considered to be a type of stimulus-responsive polymer. Attempts to graft polymerize methyl methacrylate and methyl acrylate onto starch-coated PE surfaces, under conditions similar to those used with AN, were unsuccessful. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3323-3328, 2003
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