Self-Immolative Polymers from Bio-based Monomers via Thiol−Ene Click Chemistry

The use of bio-based polymers 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 thiol-ene click polymerization. These polymers can be further used in polymer-polymer coupling to access block copolymers. Moreover, diverse responsive end-caps can be introduced through post-polymerization functionalization from a single polymer precursor. These bio-based self-immolative polymers undergo cascade degradation in response to specific stimuli through alternating 1,6-elimination and cyclization reactions.