New Initiation Systems for Step-Growth Photopolymerization

Abstract

Light-based Hot Lithography is a technique allowing the use of formulations for additive manufacturing which cannot be used at ambient temperatures. The increased temperature during the printing allows faster writing speed and higher conversion. It enables the application of systems which are too slow for ambient temperature lithography. Most systems use radical chain-growth polymerization leading to unregulated networks causing a decrease in mechanical properties. We now report a novel photobase-catalyzed initiation system for polyaddition reactions for Hot Lithography without any overpolymerisation and therefore great resolution. Additionally, the formulation showed excellent storage stability even at elevated temperatures. Therefore, our new initiation system is a promising concept for Hot Lithography giving materials with homogenous network architecture and therefore superior mechanical properties.