Common three categories of silicone sealant performance characteristics

Silicone sealant bonding, sealing and aging performance is excellent, widely used in building doors and Windows, engineering waterproof, home decoration and other aspects, but in the actual construction use process there are also many problems affecting the construction performance and quality safety, such as weak bonding, weathering cracking, bubble break glue, oil seepage tears and so on. On the one hand, the common problems in the application of silicone sealant stem from the performance and quality of the adhesive itself. In the face of the vicious price war in the adhesive market, some manufacturers use shoddy products in the production process, reducing the original performance of the product; On the other hand, it also depends on whether the operation of the sealant application process is correct, and many times the illegal sizing of the operator will directly affect the overall performance of the product. Based on the basic knowledge of production and use of silicone sealant, this paper analyzes the main problems in the application process of silicone sealant and puts forward effective solutions. 1 Silicone sealant classification Silicone glue from the packaging bottle (film) after extrusion, quickly contact with the water molecules in the air and react, according to the crosslinking agent and hydroxy-terminated polydimethylsiloxane produced by different types of small molecules, Silicone sealant can be divided into seven kinds of silicone rubber products, such as deketoxime, deacid, dealcohol, deamide, deacetone, dehydroxylamine and deamine. At present, the silicone adhesives commonly used in the domestic building materials market are three categories: deacidification type, deketoxime type and dealcoholization type. Table 1 describes the performance and characteristics of these three types of products in detail.

As can be seen from the data in Table 1, different types of silicone sealant have advantages and disadvantages, and the choice of type is particularly important in the selection process. For example, although the deacid-type silicone sealant has the advantages of surface dry, short curing time and high work efficiency, the by-product MeCOOH of this type of sealant is highly corrosive and easy to cause damage to metal and other substrates; The deketoxime type silicone sealant has good storage stability, good mechanical and chemical properties, and is popular in the silicone sealant market. Dealcoholized silicone sealant has little environmental pollution, no corrosion, tasteless, in line with the concept of modern home improvement health and environmental protection, but because of its slow vulcanization speed and short storage cycle, it is not conducive to widespread promotion.