Polymerization of a Photocleavable Monomer Using Visible Light

Area of Science:

• Polymer Chemistry
• Materials Science
• Photochemistry

Background:

• Photoresponsive polymers offer tunable properties for advanced applications.
• Controlled/living radical polymerization techniques enable precise polymer synthesis.
• o-nitrobenzyl methacrylate (NBMA) is a photocleavable monomer with potential for light-triggered applications.

Purpose of the Study:

• To investigate the controlled polymerization of NBMA using photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization.
• To synthesize well-defined PNBMA homopolymers and photocleavable amphiphilic block copolymers (BCPs).
• To evaluate the photoresponsive behavior of NBMA-based polymers after visible light polymerization.

Main Methods:

• Photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization.
• Polymerization of NBMA under visible red and yellow light.
• Synthesis of poly(o-nitrobenzyl methacrylate) (PNBMA) homopolymers and amphiphilic block copolymers (BCPs).
• Characterization of polymer molecular weight, dispersity, and UV-triggered disassembly.

Main Results:

• Controlled/living radical polymerization of NBMA was achieved under visible red and yellow light.
• Well-defined PNBMA homopolymers with controlled molecular weight and dispersity were synthesized.
• Photocleavable amphiphilic block copolymers were successfully fabricated via chain extension.
• The synthesized BCPs rapidly disassembled under UV light, confirming retained photoresponsiveness.

Conclusions:

• Visible light-mediated PET-RAFT polymerization provides excellent control over NBMA polymerization.
• NBMA retains its photocleavable properties after polymerization under visible light.
• These photoresponsive polymers are promising candidates for remote-controlled therapeutic compound delivery.