(4) Functional Silane
Structurally, the small organosilicon molecules whose main chain is -Si-O-C- are generally referred to as functional silanes. From a functional point of view, functional silanes are mostly hybrid structures, and most products contain both polar and non-polar functional groups in the same molecule, which can be used as an interface bridge between inorganic materials and organic materials or directly participate in the interaction of organic polymeric materials. It is a kind of very important and widely used auxiliaries. Functional silanes have different classification methods: they can be divided into two types: γ-substituted and α-substituted according to the relative substitution positions of active organic groups and Si; Silane, epoxy silane, and methacryloxysilane are the most widely produced and consumed domestically; they can be divided into two categories: silane coupling agent and silane crosslinking agent according to their uses.

1) Silane coupling agent: It is a type of organosilicon compound containing two different chemical properties in the molecule, which is used to improve the actual bonding strength between polymers and inorganic substances. May refer to improvements in wettability, rheology, and other handling properties. Coupling agents can also modify the interfacial region to enhance the boundary layer between organic and inorganic phases. By using a silane coupling agent, a "molecular bridge" can be set up between the interface of inorganic substances and organic substances, and the two materials with different properties can be connected together to form a bonding layer of organic matrix-silane coupling agent-inorganic matrix. Improve composite properties and increase bond strength. Silane coupling agents are widely used in adhesives, coatings and inks, rubber, casting, glass fiber, cables, textiles, plastics, fillers, surface treatment and other industries. Common silane coupling agents such as: sulfur-containing silane, amino silane, vinyl silane, epoxy silane, methacryloxy silane, etc.

2) Silane crosslinking agent: refers to a silane containing two or more silicon functional groups, which can act as a bridge between linear molecules, so that multiple linear molecules or slightly branched macromolecules and polymers can interact with each other. Bonding and cross-linking into a three-dimensional network structure, promoting or mediating the formation of covalent bonds or ionic bonds between polymer molecular chains. The cross-linking agent is the core part of the one-component room temperature vulcanized silicone rubber, which is the basis for determining the cross-linking mechanism and classification and naming of the product. According to the different condensation reaction products, one-component RTV silicone rubber can be divided into different types such as deacidification type, deketoxime type, dealcoholization type, deamination type, deamidation type and deacetone type.