Higher value films prepared from poly(vinyl alcohol) and amylose-fatty acid derivatives inclusion complexes

Authors: Fanta, George; Felker, Frederick; Hay, William; Selling, Gordon

Submitted to: American Chemical Society National Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/2/2017
Publication Date: 4/6/2017
Citation: Fanta, G.F., Felker, F.C., Hay, W.T., Selling, G.W. 2017. Higher value films prepared from poly(vinyl alcohol) and amylose-fatty acid derivatives inclusion complexes [abstract]. American Chemical Society.

Interpretive Summary: A novel method to give water resistant polymer coatings was developed using corn starch. Developing coatings that can resist the penetration of water has many obvious uses. Poly(vinyl alcohol) (PVOH) is an excellent film forming polymer which has superior gas barrier performance (keeping aromas in, oxygen out). However, PVOH is very water sensitive. Through the use of a corn starch complex, starch wrapped around another agent, the surface properties of PVOH are dramatically altered. Applying water to the PVOH/corn starch complex blended film will simply bead up on the surface rather than flow and penetrate the film. The physical properties of the film, such as elongation, may be dramatically improved. This will open up new markets for PVOH and corn starch, providing a new revenue stream for all participants in the corn value chain. While PVOH is biodegradable, the added corn starch complex will biodegrade more quickly and it can be 100% renewable. This reduces the carbon footprint of PVOH products. The corn starch complex may also be cheaper than the PVOH. This combination of performance, cost, and environmental stewardship provides a unique opportunity to manufacturers involved in the production of corn/corn starch as well as those companies interested in producing PVOH articles.

Technical Abstract: Water soluble amylose fatty acid and fatty ammonium salt inclusion complexes (AIC) were prepared by jet cooked high amylose corn starch with water soluble salts of long chain fatty acids or fatty amines. The formation of AIC was confirmed by X-ray diffraction of freeze-dried samples. After dissolution in water, AIC solutions were combined with solutions of poly(vinyl alcohol) (PVOH) at various ratios. High clarity films, using glycerol as a plasticizer, were produced. Physical properties were determined and many PVOH/AIC films had improved properties versus traditional PVOH and corn starch blends where no complex was present. The surface tension of these films was determined versus water and surprisingly it was found that the films prepared from the water soluble AIC and water soluble PVOH had much higher water contact angles when compared to the control PVOH film. While PVOH films had a water contact angle of 32°, the PVOH/AIC films had contact angles of between 70 and 89°. The oxygen permeability of the films remained exceptional. These properties allow PVOH to be used in other markets and reduces the carbon foot print for PVOH articles by replacing PVOH with a starch complex providing a new revenue stream for corn starch producers.