Melt extrusion of polyethylene nanocomposites reinforced with nanofibrillated cellulose from cotton and wood sources

Replacing petroleum‐based materials with biodegradable materials that offer low environmental impact and safety risk is of increasing importance in sustainable materials processing. The objective of this study was to produce uniform nanofibrillated cotton from recycled waste cotton T‐shirts using microgrinding techniques and compare its performance as reinforcing agent in thermoplastic polymers constructs with wood‐originated materials. The effect of the microgrinding process on morphology, crystallinity, and thermal stability of materials was evaluated by transmission electron microscopy (TEM), scanning electron microscope (SEM), X‐ray diffraction (XRD), and thermogravimetry analysis (TGA). Nanofibrillated cotton resulted in higher crystallinity and thermal stability than fibrillated bleached and unbleached softwood. All the materials were extruded with low‐density polyethylene to fabricate nanocomposite films. Nanofibrillated cotton nanocomposites had a higher optical transparency than did the wood‐based composites. The mechanical properties of the nanofibrillated cotton nanocomposites were largely improved and showed 62.5% increase in strength over the wood‐based nanofibrillated containing composites, in agreement with the higher crystallinity of the nanosized cotton‐derived filler material. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41857.