Author
Sessa, David | |
Woods, Kristen | |
Mohamed, Abdellatif | |
Palmquist, Debra |
Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 8/31/2010 Publication Date: 1/1/2011 Citation: Sessa, D.J., Woods, K.K., Mohamed, A., Palmquist, D.E. 2011. Melt-processed blends of zein and polyvinylpyrrolidone. Industrial Crops and Products. 33(1):57-62. Interpretive Summary: To make ethanol production from corn more economically feasible, it is imperative that the co-products of that industry be better utilized. Zein, the predominant prolamine found in corn, is a major co-product of corn gluten meal (wet milling) and distillers dried grains (dry milling). Zein is a potentially attractive component of biobased plastics. Plastics manufacturers and consumers alike are increasingly interested in the use of renewable resources to replace or partially replace petroleum-based plastics. Melt extrusion, based on its cost efficiency, processing ease, and high throughput capabilities, is the method of choice to meet the increasing demand for thermoplastics. Previous work has shown the compatibility of zein and certain molecular weights of polyvinylpyrrolidone (PVP) in solution-cast films. Due to the compatibility of zein and PVP in films, the work presented here focused on the melt-processing of zein with PVP to form compatible polymer blends. The objective of this investigation was to evaluate the compatibility of melt-processed zein and PVP in the absence of plasticizers, along with the impact of those blends on thermal and mechanical properties. This is the first study of a melt-processed compatible blend of zein with a synthetic polymer. This research will benefit the bioethanol industry by improving the marketability of a major co-product of this industry and therefore making the entire process more profitable. Technical Abstract: Melt-processed blends of zein with three different polyvinylpyrrolidones (PVPs) were analyzed by several methods, including DSC, TGA, SEM and mechanical property testing. Zein/PVP blends exhibited single glass transitions without evidence of the component zein and PVP peaks. Kinetic TGA data showed a greater effect on activation energy of the blends with increasing PVP concentration. SEM analysis showed no obvious inhomogeneities in the blends compared to the zein control. While mechanical property improvements were modest, the fact that 20% added PVP did not significantly reduce tensile strength suggests the presence of a compatible blend. The current work supports the conclusion that melt-processing zein with PVP produced compatible blends over a range of PVP concentrations and molecular weights, the first such melt-processed blend of zein with a synthetic polymer. |