Sulfur-containing sustainable polymers: synthetic pathways, degradation mechanisms, and multifunctional applications

Degradable sulfur-containing polymers leverage the controllable cleavage of thioester and thioether bonds under external stimuli, coupled with closed-loop recyclability, to significantly mitigate plastic pollution. The dynamic covalent adaptability of sulfur bonds within the polymer backbone, combined with the high refractive index arising from sulfur's high polarizability, enables the integration of stimuli-responsive degradation and multifunctionality. Advanced polymerization techniques, such as ring-opening polymerization and reversible addition-fragmentation chain-transfer polymerization, permit precise control over the architecture of the backbone, yielding high-performance materials with tunable thermal, mechanical, and optical properties. These materials demonstrate significant potential in biomedicine, environmental remediation, and energy storage. Focusing on molecular design, degradation control, and functional diversification, this review systematically elucidates synthetic strategies, degradation mechanisms, and frontier applications, while providing perspectives on future developments.