Click-based transparent durable films derived from tetrabrachius PDMS-bridged epoxy acrylates and surface modified nanosilica particles

Abstract

Abstract We propose a novel tetra-arm polydimethylsiloxane-bridged aryl-ether-functional epoxy acrylate (EAAE-PDMS), which was employed as a precursor to crosslink with systematic variations (0, 1, 3, 5, 15 wt.%) of thiol-functionalized silica nanoparticles (SNs) through a thiol-ene click chemistry, resulting in transparent hybrid films (EAAE-PDMS@SiO 2 ). The unique tetrabrachius structure of EAAE-PDMS can result in significantly high crosslinking densities and high gel content of their thermosetts. The introduction of PDMS bridge in the precursor backbone and the modification of SNs are simultaneously in favor of better compatibility between the organic/inorganic components, benefiting for the distinctly improved surface mechanical properties namely scratch hardness and abrasion resistance relative to common epoxy acrylates. A sound proof is the fact that either our hybrid film derived from neat EAAE-PDMS or its mixture with thiol-functionalized SNs shows an increased 5%-mass-loss temperature at least by 90 °C and up to 7-fold enhancement in the abrasion resistance relative to the silica-free EA film. Finally, the as-made films show excellent solvent and thermal resistance and strong adhesion, providing strong potentials for application in dielectric and mechanic materials.