Biobased polymeric materials prepared from cotton byproducts

Authors: Cheng, Huai; Dowd, Michael; Biswas, Atanu

Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: 3/9/2012
Publication Date: 8/16/2012
Citation: Cheng, H.N., Dowd, M.K., Biswas, A. 2012. Biobased polymeric materials prepared from cotton byproducts. American Chemical Society Symposium Series. 1105:47-62.

Interpretive Summary: Cotton is a major crop in the world. The processing of cotton and cottonseed produces a number of byproducts and waste materials. Two of them are cotton burr and cottonseed hull. Currently these materials are used as fuel, animal feed, and soil conditioning. The present authors are interested in exploring new applications. Three new applications are reviewed in this work. The first application entails the use of these materials as fillers in polymer composites. The advantages of these fillers include their lower cost and biodegradability. The second application involves the chemical conversion of these materials into cellulose acetate or mixed esters. The advantages of this process versus conventional cellulose ester processes include lower raw material cost, decreased use of organic solvent and inorganic acid, and relative ease of reaction. In the third application, these materials are converted to mixtures of carboxymethyl cellulose and carboxymethyl xylan; perhaps these products can be used as low-cost replacements of carboxymethyl cellulose.

Technical Abstract: Cotton burr and cottonseed hull are relatively inexpensive natural renewable materials from cotton and cottonseed processing. Recently several new polymer applications have been reported involving these cotton byproducts. These new developments are briefly reviewed in this article. In the first application, the cotton byproducts have been used directly as fillers in poly(lactic acid) and low-density polyethylene composites. The composites have been prepared by melt blending and extrusion. The addition of these low-cost fillers has slightly changed the composite’s thermal properties but significantly affected the composite’s mechanical properties. In the second application, the cotton byproducts have been partly converted into cellulose esters without prior chemical breakdown or physical separation of cellulose, lignin, protein, and other components. The process entails treating these materials with acetic anhydride and iodine, with no solvent involved except during sample workup. In the third application, these materials have been partly converted into carboxymethyl cellulose and carboxymethyl xylan. The potential uses of these materials are also discussed.