Ketoprofen as a photoinitiator for anionic polymerization

Area of Science:

• Polymer Chemistry
• Photochemistry
• Organic Synthesis

Background:

• Anionic polymerization typically relies on thermal initiation with strong bases and alkali metals.
• Developing metal-free photoinitiating systems for anionic polymerization remains a significant challenge.
• Ketoprofen and its derivatives offer potential for generating reactive intermediates upon photoexcitation.

Purpose of the Study:

• To present a novel photoinitiating system for anionic polymerization of acrylates.
• To utilize the photodecarboxylation of Ketoprofen derivatives for generating carbanion intermediates.
• To explore the potential for photocontrolled living polymerization using this new system.

Main Methods:

• Synthesis of Ketoprofen derivatives.
• Photodecarboxylation studies under UV and visible light.
• Confirmation of carbanion intermediates using deuterium incorporation and laser flash photolysis (LFP).
• Polymerization experiments of acrylates.

Main Results:

• Efficient photodecarboxylation of Ketoprofen derivatives was achieved.
• Carbanion intermediates were successfully generated and confirmed via deuterium labeling and LFP.
• The system demonstrated initiation in the near UV and visible regions.
• Metal-free photoinitiators were generated from photoexcitation.

Conclusions:

• A novel, metal-free photoinitiating system for anionic polymerization of acrylates has been developed.
• The system relies on the efficient photodecarboxylation of Ketoprofen derivatives to generate carbanion initiators.
• This approach offers potential for photocontrolled living polymerization, distinct from conventional anionic polymerization methods.