Reversible Radical Reservoirs in Photocurable Networks: Dormancy, Reactivation, Post-Print Growth and Long-Term Stability

Conventional radical photocuring is designed to create a network whose reactive radicals terminate, whereas reversible-deactivation radical polymerisation (RDRP) can leave dormant, reactivatable groups capable of further growth after the first cure. This creates opportunities for post-print grafting, network expansion, welding and property modification, but also introduces a qualification problem: intentional reactivation must be distinguished from uncontrolled dark polymerisation and from residual-monomer cure. Reviews of RDRP-based networks describe dormant initiating sites and photoactivated post-print transformations, while a 2026 study of conventional acrylate adhesives shows that dark polymerisation after partial photocure can depend on exposure history even without a designed living mechanism. [1,2] ER-418 therefore defines a hierarchy of evidence for radical reservoirs: chemical identity of dormant groups, reactivation under a specific stimulus, spatial control of new growth, depletion or persistence after cycling, and long-term stability when no further growth is intended.