Effects of polymer network flexibility on the kinetics of DEZ vapor phase infiltration into photo-polymerized polyacrylates

Vapor phase infiltration (VPI) enables the fabrication of novel organic-inorganic hybrid materials with distinctive properties by infiltrating polymers with inorganic species through a top-down approach. However, understanding the process kinetics is challenging due to the complex interplay of sorption, diffusion and reaction processes. This study examines how polymer network flexibility affects the kinetics of diethylzinc (DEZ) infiltration into a highly crosslinked polyacrylate copolymer system composed of two monomers: trimethylolpropane triacrylate (TMPTA) and ethoxylated trimethylolpropane triacrylate (ETPTA). The findings show that increasing the ratio of ETPTA, which enhances network flexibility, facilitates precursor diffusion, resulting in deeper infiltration and faster saturation. A reaction-diffusion transport model is employed to qualitatively interpret the experimental results and gain insights into the underlying process mechanisms, thus contributing to a better understanding of VPI kinetics.