Preparation and characterization of waterborne epoxy latexes and epoxy/(silica sol) composites

Abstract

A series of waterborne epoxy latexes was synthesized, and epoxy/(silica sol) composite latexes were prepared. The effects of functional monomer methacrylic acid (MAA) and silica sol on the latex particle size, morphology, and stability were investigated. With increasing amounts of MAA, the conversion rate increased, the particle size reduced, and the viscosity of the epoxy latexes increased. The epoxy latexes had storage stability and could be stored at room temperature for more than 6 months with a solid content variation of less than 1%. For the (silica sol)‐modified waterborne epoxy latexes, the effects of preparation techniques and silica sol content on the latexes and latex films were investigated. When the silica sol content increased, the particle size of the composite latexes decreased. The morphology investigation showed that when the silica sol content increased, the uneven surface level of the latex films was increased. The increase of elemental silica on the surface was in accord with the improvement of the water resistance of the composite latex films. The heat resistance of these films was improved as well, and their overall performance was better than that of the epoxy latex films. J. VINYL ADDIT. TECHNOL., 20:57–64, 2014. © 2014 Society of Plastics Engineers

An investigation of TiO2nanoparticles effect on morphology, thermal, and mechanical properties of epoxy/silica composites

“…These materials exhibit significant improvement of properties compared to the neat polymers due to the existence of nano‐fillers. Epoxy resins have been utilized for many years in numerous applications such as surface coatings, adhesives, electrical engineering, high voltage electrical insulation material, and painting materials due to their unique properties including good chemical resistance, thermal stability, high strength, low shrinkage on curing, good adhesion, and excellent dielectric properties . Despite the mentioned advantages, application of epoxy resin is limited due to its low thermal conductivity, high coefficient of linear expansion, high cross linking, and poor resistance to crack propagation .…”