How Are Polyurethane and Silicone Sealants Different?

Home Improvement

Polyurethane and silicone sealant are versatile materials used by professional and DIY projects. Sealants help to watertight or airtight the holes, cracks, and gaps. Sealant efficiently forms a seal and prevents liquid and fluid movement or penetration. It can be compared to caulking. Unlike caulking, sealing is flexible and used in areas where there is a possibility of expansion and contraction. 

In Singapore, Quickseal Construction Chemicals are certified distributors since 1988. They carry an array of friendly PU sealant products suitable to fulfill your industry needs. The brand is visible not just in Singapore but in Malaysia, Thailand, the Philippines, Taiwan, Indonesia, Myanmar, Sri Lanka, Indonesia, and Vietnam. 

Polyurethane versus silicone sealants 

Polyurethane is a polymer that incorporates an array of organic atoms joined by carbamate. On the other hand, silicone contains inorganic compounds. The key difference between both is at a chemical level. The properties of PU sealants include adhesion strength, hardness, flexibility, and thixotropy can be manipulated as per your needs. Its adhesive and mechanical potency can be increased to an extremely high level in comparison to silicon. 

PU sealants can handle the outdoor temperature fluctuations but over time, its properties deteriorate. Silicone is inorganic so provides high resistance to UV rays but polyurethane construction sealants with additives are available that do not deteriorate and reveal high resistance to change in color. 

Classification of PU sealants

  • Shore A hardness >45 [less than] is categorized as low modulus. Professionals use it in joints associated with rainwater roof pipes, prefabricated building elements, precast concrete blocks, and HVAC’s aluminum pipes.
  • Shore A hardness <45 [greater than] – These offer low flexibility and high surface adhesion. It is used in the automotive sector, auto glass repair, metal structure sealing, and HVAC system manufacturing. 

Professionals use PU sealants where hardening qualities and drying time is more crucial. A polyurethane sealant lasts for 7 to 10 years.