1. Classification by base material

1. Rubber type: This type of sealant is based on rubber. Commonly used rubbers are polysulfide rubber, silicone rubber, polyurethane rubber, neoprene rubber and butyl rubber.

2. Resin type: This type of sealant is based on resin. Commonly used resins are epoxy resin, unsaturated polyester resin, phenolic resin, polyacrylic resin, polyvinyl chloride resin, etc.

3. Oil-based type: This type of sealant is based on oil. Commonly used oils are various vegetable oils such as linseed oil, castor oil and tung oil, and animal oils such as fish oil.

2. Classification by vulcanization method

This family of sealants utilizes moisture in the air for vulcanization. It mainly includes one-component polyurethane, silicone rubber and polysulfide rubber. Its polymer base contains active genes. It can react with water in the air to form cross-linking bonds to vulcanize the sealant into a network structure. Moisture in the atmosphere acts as a catalyst in the sulfidation reaction.

1. Chemical vulcanization sealants: Two-component polyurethane, silicone rubber, polysulfide rubber, neoprene and epoxy resin sealants belong to this category and are generally vulcanized at room temperature. Some one-component chlorosulfonated polyethylene and neoprene sealants and polyvinyl chloride sol paste sealants, such as automotive spot welding glue, must be vulcanized under chemical reaction conditions.

2. Heat-transformation sealant: The sealant used together with plasticizer-dispersed polyvinyl chloride resin and bitumen-containing rubber is two different types of heat-transformation systems. Vinyl plasticizers are liquid suspensions at room temperature that harden by heating to a solid, while rubber-asphalt sealants are hot-melt.

3. Oxidation hardening sealant: dry surface sealant for caulking or glass installation. This type is mainly based on dry and semi-dry vegetable oil. Intermediate oils can be refined polymerized, blown or chemically modified. Using cobalt naphthenate as a drier to accelerate surface drying without hardening the interior lead naphthenate can harden both the surface and interior while manganese naphthenate makes interior hardening more effective.

4. Solvent volatilization and solidification sealant: This is a sealant based on non-viscous polymer after solvent volatilization. This type of sealant mainly includes butyl intersecting, high molecular weight polyisobutylene, acrylate with a certain degree of polymerization, chlorosulfonated polyethylene, and neoprene sealant.

5. Non-drying and permanent plastic sealant: This type of sealant usually includes polybutene, medium molecular weight polyisobutylene, high-viscosity non-oxidative adhesives such as styrene-based oil, non-drying vegetable oil, blown Semi-drying oil or butyl rubber based sealant.

3. Classification by shape

1. Paste sealant: This type of sealant is a low-grade sealant and usually uses three main materials, oil and resin, polybutene asphalt. The fixed glass commonly used to seal small windows has a maximum seam movement deformation of +5% or -5%. The validity period is generally 2 years.

2. Liquid elastomer sealant: This type of sealant includes a liquid polymer that can be formed into an elastic state by vulcanization. They have the ability to withstand repeated seam deformation. The service life of liquid elastomer sealant is generally 15 to 20 years. These sealants have high adhesion and shear strength with good flexibility at room temperature. The disadvantage is that the price is high. Usually, the two-component sealant of the primer is required to be mixed on site, and it is inconvenient to be sensitive to temperature and humidity when vulcanized.

3. Hot melt sealant: Hot melt sealant, also known as thermal construction sealant, refers to a sealant based on a blend of elastomer and thermoplastic resin. Hot melt sealants can be formulated to have properties close to liquid elastic sealants, but they are superior to liquid elastomer sealants in that they do not require the addition of vulcanizing agents

4. Liquid sealant: This type of sealant is mainly used to seal the mechanical joint surface to replace the solid sealing material paper, asbestos, cork and vulcanized rubber to prevent the leakage of the internal fluid of the machine from the joint surface, so the liquid sealant is also called liquid gasket

Classification by post-construction performance，

5. Curing sealant: This type of sealant can be divided into two categories: rigid and flexible. Rigid sealants form solids after vulcanization or setting that rarely have elasticity. Flexible sealants are elastic and soft after vulcanization. Rigid sealants are characterized by their inability to bend and usually the seams cannot be moved. Flexible sealants remain soft after vulcanization.

6. Non-curing sealant: This type of sealant is a soft coagulating sealant that remains non-drying and the tackifier continuously migrates to the surface state after construction. This glue is usually a paste and can be applied to the joint with a scraper or a brush. It can be used with sealants of different viscosities and different properties.

Fourth, according to the use of classification

1. Construction sealant: used for simple wall caulking.

2. Silicone weather-resistant sealant (neutral glue): used for waterproof sealing.

3. Silicone structural sealant: used for structural bonding and fixing.

4. Fire sealant: used for fireproof sealing.

5. Butyl glue: used for the first sealing of insulating glass.

6. Styrofoam: used for plugging and waterproofing.