In the chemical structure of polysilazane, the electronegativity of silicon and nitrogen in the silicon nitrogen bond differs by 1.2, which is between the Si-C bond and Si-O bond, and is similar to the Si-Cl bond. Therefore, the Si-N bond has about 30% ionic bond characteristics; At the same time, there is a conjugation effect (p-d overlap) between lone pair electrons on nitrogen and 3d empty orbitals on silicon; The Si-N bond energy is about 360 kJ/mol, which is lower than the bond energies of Si-O and Si-Cl bonds. Therefore, in the reaction, the Si-N bond can easily transform into other types of new bonds, which is very advantageous for developing new compounds. For example, it is prone to react with many electrophilic and nucleophilic organic substances, such as epoxy resins or phenolic resins, introducing heat-resistant nitrogen elements and heat-resistant and weather resistant Si elements into the compound, enhancing its heat resistance and weather resistance, which is very useful for coatings.

Polysilazane is widely used in coating and varnish formulations, and exhibits excellent weather resistance, UV resistance, corrosion resistance, stain resistance, anti graffiti resistance, scratch resistance, heat resistance, and other properties. The dry film thickness of polysilazane varnish is usually between 10 nm~2 μ m. Compared with amino alcohol acid varnish system and two-component polyurethane varnish system, polysilazane varnish has better light retention and weather resistance; Compared with the organic silicon modified polyester varnish system, the polysilazane varnish has superior heat resistance. The aluminum coated with polysilazane coating still has no corrosion after 2400 hours of salt spray resistance test (ISO 7253-2001); The steel coated with polysilazane coating still showed no corrosion after 2400 hours of condensation water test (ISO 6270.2-2005). The water contact angle of polysilazane coating is about 95 ° and can be maintained for a long time, while with appropriate additives, its water contact angle can be increased to over 120 °. This coating has low viscosity, solvent-free, fluorine free, excellent adhesion to most substrates, and ultra-high hardness (9H+).

When polysilazane is heated to a minimum of 450 ℃, the polymer will eventually transform into inorganic ceramics (SiOx), which have extremely high hardness (9H) and ultra-high heat resistance (up to 1800 ℃). In addition, polysilazane can form cold blend mixtures with most resins that do not undergo chemical reactions, such as thermoplastic acrylic acid, organosilicon, and mixtures of organic and inorganic polysilazane.

Polysilazane, pls check MY 9108