Submitted to: American Chemical Society Symposium Series
Publication Type: Book / Chapter
Publication Acceptance Date: 6/5/2013
Publication Date: 11/22/2013
Citation: Cheng, H.N., Dowd, M.K., Finkenstadt, V.L., Selling, G.W., Evangelista, R.L., Biswas, A. 2013. Use of cotton gin trash and compatibilizers in polyethylene composites. In: Cheng, H.N., Gross, R.A., Smith, P.B., editors. Green Polymer Chemistry: Biocatalysis and Materials II. ACS Symposium Series, vol. 1144. Washington, DC: American Chemical Society. p. 423-431.
Interpretive Summary: During cotton processing several byproducts are produced that are currently used in low-value applications, e.g., animal feed, composting, and fuel. In an effort to increase the value of these byproducts, we have examined the possibility of using these materials as fillers in polymers. The main driver is to decrease the cost of the polymers and make them more competitive in end-use applications. In this work, we studied the burr material from cotton gin trash, milled it into powder, separated it by size, and used the different size fractions as fillers in low density polyethylene. In addition, four commercially available copolymers were used as compatibilizers at lower levels. The results indicated that it was possible to make polyethylene composites with these components. There was some decrease in tensile and elongation properties but enhancement in stiffness. In view of the results, there may be a niche market for the polyethylene-cotton burr-compatibilizer composites. Thus, for applications where a polymer is needed that is stiffer and cheaper than polyethylene, the use of cotton burr filler may be a viable option.
Technical Abstract: The ginning of cotton produces 15-42% of foreign materials, called “cotton gin trash”, including cotton burr, stems, leaf fragment, and dirt. In this work we examined the mechanical properties of composites of low density polyethylene (LDPE) and cotton burr. The burr was ground into powder, and separated by size into several fractions. These were separately blended with the polymer, and then injection molded. Four compatibilizing polymers (polyethylene-g-maleic anhydride, polyethylene-co-methacrylic acid, and polyethylene-co-acrylic acid at two acrylic acid levels) were included to observe their effects on the mechanical properties. In general, the addition of these fillers to LDPE caused reductions in tensile strength and elongation, but enhancements in Young’s modulus. Improvements in tensile strength were observed for samples containing two of the compatibilizers. The results suggested that LDPE-cotton burr-compatibilizer composites may be useful in applications where reduced cost is desirable and reductions in mechanical properties are acceptable.