Silicone sealants due to its special molecular structure, the molecular structure of both inorganic and organic polymer characteristics. Silicone gum is a masterbatch by the Si-O-based polymer chain. The bond energy is 106 kcal / mol, while the usual polymer materials have small CO and CC bond energies of 80 and 85.2 cal / mol, respectively. In other words, if the Si-O chemical bond is interrupted, higher energy is inevitably required, Therefore, silicone rubber is stable, with superior anti-UV, ozone resistance, weather resistance, temperature resistance and one-component, two-component multi-application characteristics, at the same time according to the needs of the building to produce different performance requirements of the product , Especially in the structure of hidden glass curtain wall bonding applications other materials irreplaceable. And our country in the production of silicone sealant relative to the industrial development of raw materials polysulfide, polyurethane to large-scale and mature, the current silicone sealant building products accounted for more than 60% of China's construction sealant use. Foreign modified silicone products in the construction of more applications, at present, China is limited to other areas.
As early as the 60s of last century, polysulfide sealant for construction was applied to the oil and solvent resistant adhesive sealing of aircraft and aviation fields. In the 1980s, it was also applied to the sealing of construction seams in our country. Due to the cost of raw materials High, has been basically replaced by silicone products. However, polysulfide sealant has a good anti-air permeability and oil, solvent-resistant properties, is still widely used in the manufacture of insulating glass, partially used in construction sewer sewage, landfill, oil storage structure and steel structure anti-corrosion seal.
Polyurethane molecular structure of the diversity, you can create a wide range of different modulus products, suitable for bonding a lot of materials. And because of its flexible molecular chain, its resistance to vibration and fatigue performance is very good, especially for bonding different materials and the bonding of flexible materials, and also has very good low temperature resistance, in many industrial applications Very extensive. In the field of construction, the material in the United States, Japan, Germany and other developed countries close to the application of silicone products, currently in our country due to the backwardness of raw materials industry, the development of sealant products subject to certain constraints. In addition there are including butyl, acrylic, asphalt and oily resin modified less elastic seal cream products. The flexibility of these products is small, can be applied to construction joints mechanical displacement of low parts.