Enhanced silicone coatings via rapid photocatalytic hydrosilylation using a platinum complex and ITX photosensitizer

Abstract

The conventional thermocatalytic hydrosilylation method for the synthesis of organosilicon coatings suffers from high temperature and long reaction time, which hinders its wide application. Photocatalytic hydrosilylation, offering faster reactions at room temperatures, presents a compelling alternative, but demands innovative catalyst design. This work describes a novel approach centered on an easily synthesized platinum complex with 1,5-cyclooctadiene (COD) as a ligand. The platinum complex was employed as a photocatalyst within a synergistic system involving amino acids and a photosensitizer. This multicomponent approach aims to optimize both the kinetics and the application potential of photocatalytic hydrosilylation. The results revealed that the platinum complex, when combined with amino acids and a photosensitizer, achieves remarkably high silane conversion rates. Although the complex itself has good photocatalytic activity, the photocatalytic process was greatly accelerated by the addition of isopropylthiophene (ITX) as a photosensitizer. Conversion reached an impressive 89 % within just 85 s, culminating in complete curing. Silicone coatings produced via this photocatalytic route demonstrate significantly enhanced mechanical properties and thermal stability compared to those synthesized without the photosensitizer. The platinum complex demonstrates great potential for photocatalytic hydrosilylation.