Photoinitiators with low migration capability based on benzophenone

Due to the increasing safety concerns caused by migration of photoinitiators, the development of low migration photoinitiators has become a priority in the current stage. As a widely used Type II photoinitiator, benzophenone is known to cause the migration of residual small molecule initiators and co-initiators after photopolymerization, leading to safety issues and severely limiting its applications. In this work, a polymerizable photoinitiator (VBP) was synthesized by directly introducing an ethylene group into benzophenone, three different molecular weight single-component photoinitiators PVBN1-3 were synthesized based on VBP. The characterization was conducted by using spectroscopic techniques, revealing stronger absorption ability in the range of 200-330 nm compared to benzophenone. The initiation efficiency of the acrylic monomer by PVBN1-3 was evaluated by using real-time FT-IR technique. The migration stability of the cured system was investigated through immersion extraction. The results demonstrate that VBP and PVBN1-3 are a series of high-performance, low-migration photoinitiators.

Automated summary

This study focuses on the development of high-performance, low-migration photoinitiators. A polymerizable photoinitiator (VBP) was synthesized by introducing an ethylene group into benzophenone, and three different molecular weight single-component photoinitiators (PVBN1-3) were synthesized based on VBP. The results show that these new photoinitiators have stronger absorption ability compared to benzophenone and significantly reduce the migration of initiators and co-initiators, addressing the safety concerns caused by migration.