Wheat straw pre-treatments using eco-friendly strategies for enhancing the tensile properties of bio-based polylactic acid composites.

• Wheat straw optimised as feedstock for bio-composites. • Detection and removal of defects prior to bio-composite manufacture. • Significant tensile performance improvement of bio-composites. • Eco-friendly combination of physical pre-treatments to improve the surface. Individual and hybrid pre-treatments, including hot water, steam and microwave were used on wheat straw to mitigate the surface quality deficiencies for an intimate interfacial bond between substrate and Polylactic Acid matrix. Microstructural analysis showed the expansion of cells due to the pre-treatments which in turn promotes mechanical entanglement between wheat straw and PLA, thus, improving the tensile properties of bio-based composites. The tensile strength, elongation at break, elastic modulus, and toughness increased by 166 %, 18 %, 68 %, and 285 %, respectively, for hot water followed by steam pre-treated wheat straw bio-based composites compared to untreated. [ABSTRACT FROM AUTHOR]