Surface and barrier properties of hybrid nanocomposites containing silica and PEO segments

Abstract

Hybrid organic-inorganic nanocomposites containing PEO segments linked to a methacrylate network were prepared through a dual-curing process, which involved photopolymerization and condensation of alkoxysilane groups. A system based on an a,o-dimethacrylate PEO oligomer (BEMA 1400) added with methacryloyl-oxypropyltrimethoxysilane (MEMO) and tetraethoxysilane (TEOS) was used. The surface properties of the obtained films were investigated through XPS analyses and contact angle measurements. A selective enrichment of the MEMO additive towards the outermost layers of the films was evidenced either in the presence or in the absence of TEOS. SEM analyses were performed on the cross section of the films coated on PET substrates, determining the film composition at different depth by EDS analysis. The Si content was found constant, moving from the PET surface towards the air-surface of the films. The barrier properties, with respect to oxygen, of the hybrid films coated on a PET substrate were measured. A decrease of the permeability and of the oxygen transmission rate using hybrid coatings was observed.

A Simple Method for the Reinforcement of UV‐Cured Coatings via Sol‐Gel Photopolymerization

“…An alternative route was developed by Soucek and coworkers: oligomers based on TEOS or reactive organoalkoxysilane were formed in a preliminary sol‐gel step before being mixed with radically reactive resins to be subsequently photopolymerized 16–18. Acrylate silane precursors were also employed as grafting or coupling agents in a view to enhance the nanoparticles or metal alkoxides dispersion in a radically photocurable organic host matrix 19–26. Indeed, their ambifunctionality enabled their dual reaction with the organic and the inorganic components, thus ensuring a good compatibility.…”