Epoxy is familiar to everyone. This kind of organic matter is also called artificial resin, resin glue, etc. It is a very important type of thermosetting plastic. Due to the large number of active and polar groups, epoxy resin molecules can be cross-linked and cured with different types of curing agents, and different properties can be formed by adding various additives.
As a thermosetting resin, epoxy resin has the advantages of good physical properties, electrical insulation, good adhesion, alkali resistance, abrasion resistance, excellent manufacturability, stability and low cost. It is one of the most extensive basic resins used in polymer materials.. After more than 60 years of development, epoxy resin has been used in coatings, machinery, aerospace, construction and other fields.
At present, epoxy resin is mostly used in the coating industry, and the coating made with it as the substrate is called epoxy resin coating. It is reported that epoxy resin coating is a thick protective material that can be used to cover anything, from floors, major electrical appliances to small electronic products, to protect them from damage or wear. In addition to being very durable, epoxy resin coatings are generally also resistant to things such as rust and chemical corrosion, so they are popular in many different industries and uses.
The secret of epoxy coating durability
Since epoxy resin belongs to the category of liquid polymer, it needs the help of curing agents, additives and pigments to incarnate into a corrosion-resistant epoxy coating. Among them, nano oxides are often added as pigments and fillers to epoxy resin coatings, and typical representatives are silica(SiO2), titanium dioxide(TiO2), aluminum oxide(Al2O3), zinc oxide(ZnO), and rare earth oxides. With their special size and structure, these nano oxides exhibit many unique physical and chemical properties, which can significantly enhance the mechanical and anti-corrosion properties of the coating.
There are two main mechanisms for oxides nano particles to enhance the protective performance of epoxy coatings:
First, with its own small size, it can effectively fill the micro-cracks and pores formed by local shrinkage during the curing process of epoxy resin, reduce the diffusion path of corrosive media, and enhance the shielding and protective performance of the coating;
The second is to use the high hardness of the oxide particles to increase the hardness of the epoxy resin, thereby enhancing the mechanical properties of the coating.
In addition, adding an appropriate amount of nano oxide particles can also increase the interface bonding strength of the epoxy coating and extend the service life of the coating.
The role of nano silica powder:
Among these oxides nanopowders, nano silicon dioxide (SiO2) is a kind of high presence. Silica nano is an inorganic non-metallic material with excellent heat resistance and oxidation resistance. Its molecular state is a three-dimensional network structure with [SiO4] tetrahedron as the basic structural unit. Among them, oxygen and silicon atoms are directly connected by covalent bonds, and the structure is strong, so it has stable chemical properties, excellent heat and weather resistance, etc.
Nano SiO2 mainly plays the role of anti-corrosion filler in epoxy coating. On the one hand, silicon dioxide can effectively fill the micro-cracks and pores generated in the curing process of epoxy resin, and improve the penetration resistance of the coating; on the other hand, , The functional groups of nano-SiO2 and epoxy resin can form physical/chemical cross-linking points through adsorption or reaction, and introduce Si—O—Si and Si—O—C bonds into the molecular chain to form a three-dimensional network structure to improve coating adhesion . In addition, the high hardness of nano-SiO2 can significantly enhance the wear resistance of the coating, thereby prolonging the service life of the coating.