Introduction To Silicone Adhesive

- Oct 12, 2020-

Speaking of "adhesive", many people may be at a loss, but if you put it another way, "glue", they suddenly realized. Professionally called adhesives, the range of adhesives is too wide. Solid glue sticks, liquid glues, and glass glue for home decoration all belong to the category of adhesives. From small to basic necessities, to aerospace, there are adhesive applications. Silicone is a typical example.

Organosilicon compounds refer to compounds that contain Si-C bonds and at least one organic group is directly connected to the silicon atom. It is customary to connect the organic group to the silicon atom through oxygen, sulfur, nitrogen, etc. Also used as an organosilicon compound. Among them, polysiloxanes with silicon-oxygen bonds (-Si-O-Si-) as the skeleton are the most numerous, the most researched, and the most widely used type of organosilicon compounds, accounting for more than 90% of the total amount. N-Acetylethylamine is one of the important intermediates in the production of silicones.

What are the types of silicone adhesives?

(1) Silicone rubber: high temperature vulcanized silicone rubber HTV, room temperature vulcanized silicone rubber RTV

(2) Silicone resin

(3) Silicone oil

Compared with other types of polymer materials, what are the superior properties of silicone?

The basic structural unit of organic silica gel products is composed of silicon-oxygen chain links, and the side chains are connected to various other organic groups through silicon atoms. Therefore, the structure of organic silicon products contains both "organic groups" and "inorganic structures". This special composition and molecular structure makes it integrate the characteristics of organic substances and the functions of inorganic substances. Compared with other polymer materials, the most outstanding properties of silicone products are:

1. Temperature resistance

Silicone products are based on the silicon-oxygen (Si-O) bond as the main chain structure. The bond energy of C-C bond is 82.6 kcal/mole. The bond energy of Si-O bond is 121 kcal in silicone /Mole, so the thermal stability of silicone products is high, and the chemical bonds of molecules will not break or decompose under high temperature (or radiation exposure). Silicone is not only resistant to high temperatures, but also resistant to low temperatures, and can be used in a wide temperature range. Whether it is chemical properties or physical mechanical properties, the change with temperature is very small.

2. Weather resistance

The main chain of organic silicon products is -Si-O-, there is no double bond, so it is not easy to be decomposed by ultraviolet light and ozone. Silicone has better thermal stability and radiation resistance and weather resistance than other polymer materials. The service life of silicone in natural environment can reach several decades.

3. Electrical insulation performance

Silicone products have good electrical insulation properties. Their dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistivity and surface resistivity are among the best in insulating materials, and their electrical properties are affected by temperature and frequency. The impact is very small. Therefore, they are a kind of stable electrical insulating materials, which are widely used in the electronics and electrical industries. In addition to excellent heat resistance, silicone also has excellent water repellency, which guarantees high reliability of electrical equipment used in wet conditions.

4. Physiological inertia

Polysiloxane compounds are among the most inactive compounds known. They are very resistant to biological aging, have no rejection reaction with animal bodies, and have good anticoagulant properties.

5. Low surface tension and low surface energy

The main chain of organosilicon is very flexible, and its intermolecular force is much weaker than that of hydrocarbons. Therefore, it has lower viscosity than hydrocarbons of the same molecular weight, weak surface tension, low surface energy, and strong film-forming ability. This low surface tension and low surface energy are the main reasons for its many applications: hydrophobic, defoaming, foam stability, anti-sticking, lubrication, glazing and other excellent properties.

It is precisely these excellent properties of silicone that silicone products are widely used in military industry/aerospace/construction/electronics and electrical/automotive/leather/textile/chemical/medical and medical industries.