From waste rubber to value polybutadiene modification for circular materials.

Synthetic rubber waste poses a growing environmental challenge due to its cross-linked, non-recyclable nature. This Perspective examines emerging post-polymerization modification strategies for linear polybutadiene and vulcanized rubber, spanning catalytic, metal-free, and catalyst-free approaches, and evaluates their alignment with Green and Circular Chemistry principles. By coupling sustainability metrics with assessments of technological readiness, we highlight current limitations and opportunities for the real-world implementation of these approaches. Looking ahead, we outline how integrating mechanochemistry, machine learning, and life-cycle assessment can enable scalable, low-impact transformations that recast vulcanized polybutadiene from waste to resource, paving the way toward a circular elastomer framework.