Preparation and evaluation of composites containing polypropylene and cotton gin trash

Authors: GE, CHANGFENG - Rochester Institute Of Technology; Cheng, Huai; MIRI, MASSOUD - Rochester Institute Of Technology; HAILSTONE, RICHARD - Rochester Institute Of Technology; FRANCIS, JOHNATHAN - Rochester Institute Of Technology; DEMYTTENAERE, SHAO - Rochester Institute Of Technology; ALHARBI, NAJAT - Rochester Institute Of Technology

Submitted to: Journal of Applied Polymer Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/19/2020
Publication Date: 7/7/2020
Citation: Ge, C., Cheng, H.N., Miri, M.J., Hailstone, R.K., Francis, J.B., Demyttenaere, S.M., Alharbi, N.A. 2020. Preparation and evaluation of composites containing polypropylene and cotton gin trash. Journal of Applied Polymer Science. 137(38):1-13. https://doi.org/10.1002/app.49151.
DOI: https://doi.org/10.1002/app.49151

Interpretive Summary: Cotton gin trash is an abundant byproduct of cotton processing, and it is beneficial to seek higher value applications for it. In this work, we prepared and evaluated the composites made from polypropylene and cotton gin trash and studied their mechanical, thermal and morphological characteristics. In general, the addition of gin trash to polypropylene reduced tensile strength and elongation, but enhanced Young’s modulus. The gin trash was then washed with toluene and derivatized with maleic anhydride-grafted MAPP. New composite films were made with the modified gin trash, and several composites showed improved mechanical properties. These polypropylene-gin trash composites may be useful in applications where reduced cost and enhanced stiffness are desirable and reductions in tensile strength and elongation are tolerable.

Technical Abstract: In an effort to enhance the utilization of agro-based materials in industrial products, we have investigated the potential use of cotton gin trash (GT) as a filler in polypropylene (PP). GT was modified by two methods: toluene washed only, and toluene washed and reacted with maleic anhydride-grafted polypropylene (MAPP). These GT samples were blended and extruded with PP in various weight ratios. Additionally, MAPP and EVA were added to investigate if they altered the performance of the GT/PP composites. It was found that the PP composite with 10 wt. % and 20 wt.% modified GT yielded tensile strengths close to that of the neat PP. The combined toluene/MAPP treatment enabled GT to reach a higher loading of 20 wt.% in the PP matrix without compromising the tensile strength. The PP/GT composite exhibited significantly higher tensile modulus and lower elongation at break than the neat PP. It was also found that the addition of an adequate amount of MAPP improved the tensile strength of the GT/PP composite. Moreover, the PP composite containing 20% GT treated with toluene and MAPP resulted in more uniform morphologies as observed from the less pronounced additional melting peak in the DSC measurements, and their thermal behavior was most similar to polypropylene. Finally, this work suggests that the use of 10-20 wt. % GT treated with toluene and MAPP, blended with 5 wt.%-10 wt.% MAPP, in the PP matrix offered a well-balanced and useful PP/cotton gin trash composite.