Single component polyurethane sealant, as known as a single component, hydrophilic, water activated, hydro active, expandable, gungrade waterstop, is also called single component polyurethane hydrophilic expansion waterproofing sealant. When in contact with water, the sealant expands and produces an expanding pressure. The pressure between the expanded sealant and the surrounding concrete structure prevents water penetration through the joint and provides a durable waterproofing solution. Advantages Based on the physical and chemical properties of the polyurethane sealant, it has many advantages. Such as: Expansion rate. The polyurethane sealant has a strong expansion capacity. It can expand to 220% or 300%, 400%, 500%, even 600% of its own volume. Strong adhesion. It can used to steel, HDPE, PVC, and other common building materials, and it also effective to damp surfaces. Good weather resistance. It has low temperature flexibility, and its service life of up to 15 to 20 years. Environmentally non-toxic. It has good chemical resistance, and it tested can be resistant to hydrochloric acid, salt water, sodium carbonate, potassium hydroxide and other chemicals. In addition, it is safe and non-toxic when in contact with drinking water, belongs to environmentally friendly products. Ease to use. It can be applied with a standard caulking gun. Application Polyurethane sealant is widely used in construction, transportation and other industries. Such as the following usage: Caulking agent. The polyurethane sealant is used as caulking agent in the construction of subways, tunnels, underground parkings and other projects. Sealing waterproof. In building construction, it can play a role of sealing waterproof for doors and windows, exterior walls and other parts. Water stop. It can be used as water stop when punctures are found in plumbing, sewer lines and other utility pipes.