From the point of function, functional silane is a hybrid structure more, most of the products in the same molecule containing polar and nonpolar two types of functional groups at the same time, can be a interface bridge of inorganic material and organic material or directly involved in the organic polymer alloy material of the crosslinking reaction, thus greatly improve the material performance, is a kind of very important and very versatile aid agent. According to their use, they can be divided into silane coupling agent and silane crosslinking agent.
Silane coupling agent: a class of organosilicone compounds containing two different chemical properties in the molecule, used to improve the actual bonding strength of the polymer to the inorganic, which may refer to the improvement of the real adhesion, but also may refer to the improvement of the wetting, rheological and other operational properties. The coupling agent can also modify the interface region to strengthen the boundary layer between organic and inorganic phases. By using silane coupling agent, a "molecular bridge" can be built between the interface of inorganic material and organic material, and the two materials with different properties can be connected together to form a binding layer of organic-silane coupling agent and inorganic matrix, so as to improve the properties of composites and increase the bonding strength. Silane coupling agent is widely used in adhesives, coatings and inks, rubber, foundry, glass fiber, cable, textile, plastics, fillers, surface treatment and other industries. Common silane coupling agents include sulfur silane, aminosilane, vinyl silane, epoxy silane, methacryloxysilane, etc.
Silane crosslinking agent: refers to the silane containing two or more silicon functional groups, can play a bridging role between linear molecules, so that a number of linear molecules or mild branched chain macromolecules, macromolecules cross-linked to form a three-dimensional network structure, promote or mediate the formation of covalent bonds or ionic bonds between polymer molecular chains. The crosslinking agent is the core part of the single component room temperature vulcanized silicon rubber, and it is the basis to determine the crosslinking mechanism and the classification and naming of products. According to the different products of the condensation reaction, the single component RV silicone rubber can be divided into different types, such as deacidification type, deketone oxime type, dealcoholization type, deamination type, deamidation type and deacetone type.
Sulfur-containing silanes have become the most productive varieties of functional silanes in China, followed by all kinds of crosslinking agents. Among other varieties, aminosilanes, vinylsilanes and epoxy-silanes are the most productive in turn.
There are many kinds of functional silanes, whose uses are mainly determined by the types and structures of functional groups, and the main application fields include composite materials, rubber processing, plastics, adhesives, coatings and surface treatment. At present, silane has been used for more than 70 years. From the initial glass fiber treating agent, silane has been widely used in various fields.