Epoxy Sol-Gel Hybrid Thermosets

Abstract

Sol-gel methodologies are advantageous in the preparation of hybrid materials in front of the conventional addition of nanoparticles, because of the fine dispersion of the inorganic phase that can be reached in epoxy matrices. In addition, the use of organoalkoxysilanes as coupling agents allows covalent linkage between organic and inorganic phases, which is the key point in the improvement of mechanical properties. The sol-gel process involves hydrolysis and condensation reactions under mild conditions, starting from hydrolysable metal alkoxides, generally alkoxy silanes. Using the sol-gel procedure, the viscosity of the formulation is maintained, which is an important issue in coating applications, whereas the transparency of the polymer matrix is also maintained. However, only the proper combination of the chemistries and functionalities of both organic and inorganic structures leads to thermosets with the desired characteristics. The adequate preparation of hybrid epoxy thermosets enables their improvement in characteristics such as mechanical properties (modulus, hardness, scratch resistance), thermal and flame resistance, corrosion and antimicrobial protection, and even optical performance among others.

Improved epoxy thermosets by the use of poly(ethyleneimine) derivatives

“…The formation of the inorganic silica structure in epoxy hybrids can take place before or after the curing process. Many sol-gel hybrid materials have been prepared by different curing methodologies [191]. In order to obtain good mechanical properties, the compatibility of organic and inorganic structures by the formation of covalent bonding is an essential condition, and for this reason, the use of coupling agents is needed [192,193].…”

Epoxy resin coatings modified by ionic liquid. Study of abrasion resistance

“…Roomtemperature ionic liquids play multiple roles when used as additives of epoxy thermosets [3], ranging from catalysts and curing agents [4] to plasticizers or precursors of conducting [5][6][7] and more sustainable materials [8]. Very recent studies are focusing on the effect of different fillers on the tribological performance of epoxybased bulk materials, coatings and films [9][10][11][12][13][14]. From the point of view of improving the poor tribological performance or epoxy resin, ILs have shown their ability to reduce the brittleness of the bulk epoxy matrix materials, reducing friction coefficients and protecting against wear [15][16][17][18][19][20].…”

Mechanical and Thermal Stability of Epoxy – TEOS Hybrids Materi-als using Sol-Gel Method

“…New materials, organic and inorganic components can interpenetrate each other in scales ranging from a few micrometers to a few nanometers. In general, organic and inorganic structures are covalently bonded, more or less strongly [1]. Epoxy composites, which are hybrid organic-inorganic materials, have a wide range of engineering applications that require a high strength to weight ratio, low cost and ease of fabrication [2].this reduces the stable lifetime of these materials.…”