Dual-Pathway Strategy for Click-Type Functionalization and Programmable Polymer Deconstruction.

Area of Science:

• Macromolecular Engineering
• Polymer Chemistry
• Materials Science

Background:

• Developing functional polymers with precise control over degradation is a significant challenge.
• Existing methods often lack modularity or stimulus-responsive degradation capabilities.

Purpose of the Study:

• To present a molecular design strategy integrating orthogonal postpolymerization modification with stimulus-responsive backbone degradability.
• To synthesize a dual-functional monomer enabling both modular functionalization and programmed degradation.

Main Methods:

• Synthesized a dual-functional monomer, triketone-lipoic acid (TKLA), by incorporating a β-triketone (TK) moiety into an α-lipoic-acid-derived 1,2-dithiolane.
• Utilized photoinduced electron/energy-transfer reversible addition-fragmentation chain-transfer (PET-RAFT) copolymerization to create well-defined copolymers.
• Employed β-triketone-amine condensation for modular functionalization and reducing conditions for disulfide backbone cleavage.

Main Results:

• Achieved well-defined copolymers with pendant TK groups and disulfide-rich backbones in a single step.
• Demonstrated quantitative reaction of TK groups with amines to form dynamic β,β'-diketoenamines (DKEs) for modular substituent installation.
• Showcased selective backbone fragmentation under reducing environments, preserving side-chain chemistry.

Conclusions:

• Established a molecular design strategy for functional, recyclable, and stimuli-responsive polymer architectures.
• The integration of TK-amine condensation and lipoic acid-based degradability offers a versatile platform for advanced polymer synthesis.
• This approach enables controlled deconstruction and reconfiguration of polymer functionalities.