Upcycling acrylonitrile-butadiene-styrene Vitrimer ‘in melt’ using a dynamic crosslinker

Abstract

The perception of a sustainable plastic closed-loop circular economy hinges on the transformation of post-consumer recycled (PCR) commodity plastics. Among those, acrylonitrile butadiene styrene (ABS), a widely utilized engineering plastic, can be economically and efficiently upcycled to mark a significant step forward. Very few concrete solutions have been proposed so far for adopting end-of-life ABS into reusable products, mainly due to deterioration in mechanical properties of PCR ABS after subsequent recycling. Our approach introduces a distinctive strategy of creating durable and recyclable dynamic covalent adaptable network (CAN) termed as PCR ABS Vitrimers, all achieved through a melt-based process which holds promise for industrial viability and economic feasibility. In a first of its kind, a designer bio-based crosslinker, imine containing castor oil (iCO) having dynamic imine linkages as CAN was synthesized to form PCR ABS Vitrimers ‘in melt’ resulting in an upcycled ABS with 15% and 19% improvement in ultimate tensile strength and Young’s modulus respectively, in the Vitrimers. Our designer giant crosslinker, besides offering a transient network imparts re-processibility to the formed PCR ABS Vitrimers via melt with better mechanical integrity. This research endeavours to tackle a long-standing obstacle in upcycling PCR ABS in its melt state by producing a more robust, resilient, and solvent-resistant material derived from PCR ABS waste.