& nbsp; & nbsp; What is MS glue
  & nbsp; & nbsp; MS glue is the abbreviation for silane modified polyether glue, mainly composed of MS polymer as the base polymer, combined with fillers, plasticizers, and other functional additives to form a single component or two-component elastic sealant. It is a new generation of building sealant developed after silicone glue (SR) and polyurethane glue (PU). Mainly used in the fields of bonding, joint filling, seam sealing, waterproofing, reinforcement, etc. in construction engineering and decoration. With the deepening of people's understanding of the advantages of MS adhesive, its application in the fields of refrigerated trucks, containers, and elevators is also constantly expanding.
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  & nbsp; & nbsp; The Development History of MS Adhesive
  & nbsp; & nbsp; In 1979, Kaneka, a Japanese chemical industry company, successfully developed a basic polymer for silicone modified polyether sealant (also known as terminal silane based polyether sealant).
  & nbsp; & nbsp; In 1980, Kaneka Company in Japan was the first to prepare elastic sealant based on terminal silane polyether, and began promoting its application in large and high-end buildings in 1981.
  & nbsp; & nbsp; After 1982, Japan, the United States, and various European countries competed for research on end silicone polyether base polymers and their elastic sealants and adhesives, promoting the rapid development of MS adhesives.
  & nbsp; & nbsp; In recent years, MS adhesive has emerged as a rising force, with an increasing number of production enterprises and rapid technological progress, occupying an increasingly large share in the world building sealant market.
  & nbsp; & nbsp; MS adhesive composition
  & nbsp; & nbsp; The main raw materials of MS glue include: alkyl terminated polyether (MS prepolymer), plasticizers (dioctyl phthalate, abbreviated as DOP; dibenzyl phthalate, abbreviated as DCP; dibutyl phthalate, abbreviated as DBP, etc.), gas-phase white carbon black, catalyst, silane coupling agent, anti-aging agent, water removal agent, etc.
  & nbsp; & nbsp; The strength of MS prepolymer itself is not high. If it is used to prepare sealant, fillers that can provide certain reinforcement must be added. The type and amount of filler significantly affect the mechanical and rheological properties of the sealant. In the preparation of transparent MS adhesive, white carbon black is usually used as a reinforcing filler.
  & nbsp; & nbsp; The main function of plasticizers is to weaken the van der Waals forces between polymer molecules, thereby increasing the mobility of polymer chains and reducing their crystallinity. This increases the shaping of polymers, resulting in a decrease in their hardness, modulus, softening temperature, and brittleness temperature, as well as an increase in elongation, flexibility, and flexibility. Adding DOP to sealant can increase fluidity, reduce hardness, and adjust modulus. However, excessive addition can not only cause migration and leakage of DOP, but also affect the sagging and mechanical properties of the sealant.
  & nbsp; & nbsp; Catalysts have two main functions: (1) accelerating cross-linking and curing at room temperature, shortening the curing time; (2) Endow the adhesive with good storage stability. MS gel catalysts mainly include stannous octoate, tin butyrate, dibutyltin diacetate, dibutyltin dioctate, chelating tin, dibutyltin dilaurate, trialkylamine, etc. The most common catalyst among them is dibutyltin dilaurate.
  & nbsp; & nbsp; The molecules of silane coupling agents have two different functional groups with different chemical properties. The alkoxy group at one end can react with moisture in the air to generate active silanol groups, which can then undergo condensation reactions with hydroxyl groups on the surface of the substrate to form stable chemical bonds; The reactive functional groups on the other end can react and bind with the polymer, forming a bridge like effect between the sealant and the substrate. Meanwhile, silane coupling agents can also serve as crosslinking agents for polymer curing reactions, improving the crosslinking density of the final MS adhesive product.
  & nbsp; & nbsp; The molecular chains of MS polymers are mainly composed of C& C key and C‐ Composed of O, its bond energy is relatively high compared to Si— The low O bond makes it easier to break under UV light, which can affect the aging resistance of MS adhesive. Therefore, it is necessary to add anti-aging additives to the formulation system to enhance its aging resistance.
  & nbsp; & nbsp; The moisture curing mechanism of single component MS sealant determines that the less moisture in its system, the better, ensuring that its performance remains basically unchanged during the storage period (360 days). Ethylene trimethoxysilane (WD-21) or ethylene triethoxysilane is commonly used as a sealant water removing agent. Due to its high reactivity with water, the alkoxysilane can quickly consume the water in the system and improve the storage stability of the sealant.