What are the advantages and disadvantages of polyurethane sealant?
As a type of sealant, polyurethane sealant is mainly made of polyurethane prepolymer and polyurethane rubber. This type of sealant has high tensile strength, excellent elasticity, wear resistance, oil resistance and cold resistance, but poor water resistance, especially alkaline water resistance. It can be divided into three types: heating vulcanization type, room temperature vulcanization type and hot melt type. Among them, the room temperature vulcanization type is divided into single component and two components. It is widely used as a caulking sealing material in buildings, squares, and roads, as well as in automobile manufacturing, glass installation, electronic filling, submarines and rockets.
Polyurethane sealant has the following advantages:
1. Polyurethane sealant has good wear resistance after use, which can reduce friction during use and provide service life.
2. The performance can be adjusted at will. If the user is not sure about the proportion of self-adjustment, he can cooperate with a company with customization strength, such as Cosmore, which focuses on the research of polyurethane sealants and provides customized polyurethane sealant application solutions. It has a wide range of uses and can be applied to new energy, military, medical, aviation, shipbuilding, electronics, automobiles, instruments, power supplies, high-speed rail and other industries.
3. The service life is very long, and the performance will not change in 15 to 20 years in a normal use environment.
4. After curing, polyurethane sealants have good oil resistance and biological aging properties, and can be used in a variety of fields.
In addition, low-temperature softness; wide adjustable range of performance; high mechanical strength; polyurethane sealants, good adhesion; good elasticity, excellent recovery, suitable for dynamic joints; good weather resistance, moderate price.
Polyurethane sealants also have some disadvantages. Not heat-resistant for a long time; light-colored formulas are easily affected by ultraviolet light aging; the storage stability of single-component glue is greatly affected by packaging and the outside world, and usually cures slowly; bubbles and cracks may occur in high-temperature hot environments; primer is required in many occasions. At the same time, polyurethane sealant has poor water resistance, especially poor alkaline water resistance.