Low-Migration Compounds with Amine Functionality as Coinitiators of Radical Polymerization

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Two-component camphorquinone (CQ)/aromatic amine systems are widely used in photopolymerization.
• Concerns exist regarding the toxicity and leaching of aromatic amines from these systems.
• Dental materials require safe and effective photoinitiation systems.

Purpose of the Study:

• To develop novel, non-leaching coinitiator systems for dental methacrylate resins.
• To create a camphorquinone (CQ)-based system with copolymerizable amines.
• To ensure free radical polymerization under blue light with minimal migration.

Main Methods:

• Molecular modeling to design hydrogen donors with low C─H bond dissociation energy.
• Chemical modification to incorporate copolymerizable methacrylate groups into amines.
• Synthesis and performance comparison of the novel photoinitiation system (PIS) against CQ/ethyl-4-dimethylaminobenzoate (EDB).
• Mechanistic investigation using molecular orbital calculations and electron spin resonance (ESR).

Main Results:

• Successful synthesis of a novel, copolymerizable coinitiator.
• Demonstrated effectiveness of the new PIS in dental methacrylate resin polymerization.
• Confirmation of low migration and leachability of the novel coinitiator.
• Elucidation of the reaction mechanism of the proposed PIS.

Conclusions:

• The developed CQ-based PIS with copolymerizable amines offers a safer alternative to traditional systems.
• This innovation addresses concerns about aromatic amine toxicity and leaching in photopolymerized dental materials.
• The study provides a new strategy for designing low-migration photoinitiators for various applications.