Background

Thermal polymerization is commonly used in a wide range of industries to provide surface coatings to materials. However, true thermal polymerization can be difficult to establish since trace impurities in the monomers or reaction vessel often react as initiators. In addition, high temperatures, and harsh reaction conditions are required. Stereospecific polymerization, biomaterial synthesis is not possible when using thermal polymerization methods due to side reactions and/or branched macromolecules. This has led to the development of photoinitiating systems which can be conducted at lower temperatures and with milder conditions. Alternative systems of photochemical generations of free radicals and cations have been developed and used in industry, however, there have been few systems developed that use anionic photoinitiating species. These anionic photoinitiating systems consist of organometallic complexes or the generation of Lewis bases from the corresponding salts. There has not been a system developed that uses metal‑free and carbanion‑induced photopolymerization. If this system was developed, through careful selection of anionic photoinitiators, there would be high quantum yields, a long lifetime of polymerization, and a broad scope of practical applications.

Technology Overview

Researchers at the University of Victoria have developed a photoinitiating system for anionic polymerization based on the photogeneration of long‑lived carbanions of Ketoprofen and related derivatives. This novel photoinitiating system can be implemented to use eco‑friendly monomers, low‑cost sunlight initiation while maintaining scalable polymer synthesis. The system could be applied to the development of dental fillings, stereolithography, photoresist materials and biomaterials.

Benefits

• High quantum yields
• A long lifetime of polymerization
• Scalable polymer synthesis
• Reaction runs at low temperatures
• Reaction requires mild conditions

Applications

• Stereolithography
• Photoresist materials
• Biomaterials