Preparation and evaluation of composites containing polypropylene and cotton gin trash

Composites of polypropylene (PP) and cotton gin trash (GT) were prepared to enhance the utilization of agro‐based materials in industrial products. GT was modified by two methods: toluene washed only, and toluene washed and treated with maleic anhydride‐grafted polypropylene (MAPP). These GT samples were extruded with PP, including MAPP and ethylene/vinyl acetate copolymer in various weight ratios (32 composites total). The PP composites displayed tensile strengths close to that of the neat PP, and exhibited higher values of tensile modulus and lower elongation at break than the neat PP. Based on DSC measurements, the PP composites containing 10 wt% GT exhibited two crystalline regimes, while those containing 20 wt% GT were similar in crystallinity to that of the neat PP. The composites were also characterized using SEM, TGA, water absorption tests, and contact angle measurements. These composites represent a more sustainable alternative to neat, fossil fuel‐based PP.