Combining reactivity with biocompatibility: using aliphatic alpha-ketoesters as photoinitiators for the radical photopolymerization in (meth)acrylate resins

Abstract

Photopolymerization of (meth)acrylate-based resins has developed into an important curing method, resulting from its high energy efficiency and short curing times. Apart from coatings, this technology has opened the window for more complex applications including additive manufacturing, electronics and tissue engineering. Generally, photoinitiators are based on aromatic benzoyl chromophores. However, the use of these state-of-the-art photoinitiators is becoming more regulated as their degradation and recombination products are suspected of being mutagenic or cancerogenic to humans. Therefore, we have developed a set of purely aliphatic, multifunctional photoinitiators based on non-toxic α-ketoesters. Compared to the industrially used benzophenone-amine photoinitiator system, the developed α-ketoesters show higher curing speed and monomer conversions. Additionally, both the photoinitiators and their degradation products show high biocompatibility.