Synthesis of poly(ester disulfide)s from S8-involved step-growth addition polymerization at ambient temperature

Elemental sulfur (S8), an abundant petroleum byproduct, is leveraged as a linchpin monomer in an organobase-catalyzed step-growth addition polymerization with dithiols and diacrylates at ambient temperature. This method enables the scalable synthesis of poly(ester disulfide)s—featuring alternating ester and disulfide linkages—with exceptional atom economy ( > 95% yield), Mn up to 42.0 kDa, and dual functionality: biodegradable ester units and stimuli-responsive disulfides. Mechanistic studies reveal a chemoselective three-component coupling involving S8 ring-opening, disulfide anion formation, and Michael addition, quantitatively generating symmetric and asymmetric disulfides in near-equimolar ratios. Thermal and mechanical characterizations of the poly(ester disulfide)s reveal programmable properties: High thermal stability (Td,5% = 248–281 °C), tunable phase behavior (amorphous Tg = −64 °C to semicrystalline Tm = 142 °C), and reductive degradation. By overcoming traditional limitations of harsh conditions and monomer scope, this strategy establishes S8 as a versatile feedstock for functional polymers, opening avenues for dynamic materials in biomedicine and environmental remediation. The synthesis of high molecular weight poly(disulfide)s typically requires harsh conditions or the complex cyclic disulfide monomers. Here, the authors report a mild, room-temperature multicomponent polymerisation using elemental sulfur to yield high molecular weight poly(ester disulfide)s