Self‐Immolative Polymers Derived from Renewable Resources via Thiol−Ene Chemistry

The development of polymers from renewable resources is a promising approach to reduce reliance on petrochemicals. In addition, depolymerization is attracting significant attention for the breakdown of polymers at their end‐of‐life or to achieve specific stimuli‐responsive functions. However, the design of polymers incorporating both of these features remains a challenge. Herein, we report a new class of self‐immolative polymers based on lignin‐derived aldehydes via a simple thiol‐ene polymerization. These self‐immolative polymers undergo cascade degradation in response to specific stimuli through alternating 1,6‐elimination and cyclization reactions. The two methoxy substituents on the syringaldehyde monomer accelerated the desired depolymerization reaction, while enhancing stability against undesired backbone hydrolysis. Moreover, diverse responsive end‐caps could be introduced through post‐polymerization functionalization from a single polymer precursor.