Corn silk fibre reinforced PLA biocomposites for automotive application

Abstract

Corn silk (CS), an agricultural byproduct obtained after the processing of corn, is usually dumped as waste. Worldwide there is a growing concern to utilise this waste for making value-added products. This work tried to improve the functional properties of corn silk fibres and utilise them to fabricate biocomposites for automotive applications. Raw corn silk fibres were alkali treated (2%, 45 min) to achieve around 11% improvement in tensile strength, 14% improvement in elongation-at-break and 26% reduction in initial modulus. The alkali-treated fibres were further processed to prepare bi-directional carded webs which were ultimately reinforced in PLA matrix utilising compression-moulding technology. The biocomposites developed with different mass fractions (10% to 50%) of alkali-treated corn silk fibres were evaluated for their functional properties. The biocomposite, formulated with 40% mass fractions of treated corn silk fibre and poly(lactic) acid, exhibited the highest mechanical performance—tensile strength (74.57 MPa), Young’s modulus (4.28 GPa), Flexural strength (442.45 MPa), breaking elongation (2.04%) and impact strength (3.2 kJ/m²). The biocomposites were also found to be thermally stable with no significant weight loss till 319 °C and 98.49% final weight loss at the end of 780 °C. Those biocomposites exhibited biodegradability with 2.73% weight loss and 13.11% strength loss in 30 days of burial in soil. The biocomposite reinforced with 40% alkali-treated corn silk fibres demonstrated high potential for automotive namely door panels, exterior under-floor panels, instrument panels, internal engine covers, packaging trays, seat backs, etc. Moreover, this study advances sustainable biocomposites by enhancing CS fibre properties, achieving superior mechanical strength, thermal stability, and biodegradability for automotive applications.