Dual‐curable unsaturated polyester inorganic/organic hybrid films

Abstract

An unsaturated polyester, based on maleic anhydride, 1,6-hexanediol, and trimethylol propane, was formulated with tetraethylorthosilicate (TEOS) oligomers and a coupling agent to prepare inorganic/organic hybrid films. TEOS oligomers were prepared through the hydrolysis and condensation of TEOS with water, and 3-(triethoxysilyl)propylisocyanate was used as the coupling agent between the organic and inorganic phases. The hybrid materials were cured by moisture via sol-gel chemistry and by the UV curing of unsaturated polyesters. To compare the properties of the moisture-cured inorganic/organic hybrid films, a conventional 2K polyurethane system was also prepared. The tensile, adhesion, abrasion, and fracture toughness properties were investigated as functions of the coupling agent and relative amount of UV cure versus thermal cure. Although no difference could be observed in the tensile properties, the abrasion resistance, fracture toughness, and adhesion were enhanced by the incorporation of TEOS oligomers into polyurethane films. Also, the abrasion resistance, fracture toughness, and tensile properties were increased with both moisture and UV exposure.

UV-Curable Coating Technologies

“…Inorganic silicate oligomers may function as a reactive diluent and not only help to reduce viscosity of the resin but also may increase the mechanical properties of the films. 38 UV-moisture dual-curable inorganic-organic hybrid coatings based on UPE binders and silicate-clusters were successfully prepared. In situ formed nano-to microsize inorganic clusters increased the abrasion resistance, adhesion, tensile strength and fracture toughness of the films.…”

Synthesis and characterization of hybrid films from hyperbranched polyester using a sol–gel process

“…Numerous organic–inorganic hybrids based on linear polymers and thermosetting polymers have been examined in literature. However, only a few studies have been reported on hybrids based on polyesters, either linear, unsaturated or hyperbranched polyesters . Ester groups in polyester chains are not strong enough to form hydrogen bonds with silanols, so the use of a type of polyester which contains hydroxyl groups is of a great interest to increase the interfacial forces between the polymer and the silica network.…”

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

“…Until now, these hybrid sol‐gel photomaterials were mainly synthesized from radically reactive organotrialkoxysilanes through a two‐step process: a preliminary sol‐gel step in solution was followed by the photopolymerization of the resulting functional polysilsesquioxane, thus affording a type‐II polysiloxane/poly(meth)acrylate hybrid film 10–15. 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.…”