Tuning the mechanical properties of epoxy-acrylate core-shell nanostructured films via epoxy concentrations in the core layer

Epoxy-acrylate (EA) core-shell nanoparticles have gained significant attention recently due to their dual unique properties, especially in coating applications. In this study, we investigate how varying epoxy (EP) concentration in the core phase impacts the mechanical properties of films containing EA core-shell nanoparticles. The nanoparticles can be synthesized through multi-stage seeded emulsion polymerization. The TEM images revealed similar particle morphology and size in all EA emulsions. DSC analysis confirmed the successful synthesis of core-shell particle morphology with two Tg values (~12 °C and ~60 °C) observed for the core and shell layers, respectively. We observed an increase in the glass transition temperature (Tg) values of the shell phase with higher EP (EP) content in the core phase. The use of EP-based copolymers raised the Tg values of the shell phase, significantly affecting the film formation behavior and their mechanical properties through interlayer crosslinking. Tensile modulus values for the films ranged from 200 to 500 MPa, marking the highest modulus reported for cast films of nanostructured films. Our approach offers a straightforward and versatile method for producing high-modulus EA core-shell films with customizable mechanical properties, making them ideal for enhancing wood coating performance.