Silicone | Vitamins for Life/Industry (II)


II. Physical Structure


Silicone materials have unique structures:


Sufficient methyl groups on Si atoms shield the high-energy polysiloxane main chain.


C-H has no polarity, which makes the interaction between molecules very weak.


The bond length of Si-O is longer and the bond angle of Si-O-Si is larger.


Si-O bond is a covalent bond with 50% ionic bond characteristics (covalent bond has directionality, ionic bond has no directionality).


3. Performance Introduction


Basic introduction


The basic structural unit of silicone products is composed of silicon-oxygen chains, while the side chains are connected with other organic groups through silicon atoms. Therefore, the structure of organic silicon products contains both "organic group" and "inorganic structure". This special composition and molecular structure makes it integrate the characteristics of organic matter and the functions of inorganic matter. Compared with other macromolecule materials, the most outstanding properties of organosilicon products are


Temperature Resistance Characteristic


Silicone products are mainly composed of silicon-oxygen (Si-O) bond. The bond energy of C-C bond is 82.6 kcal/molecule. The bond energy of Si-O bond is 121 kcal/molecule in silicone. Therefore, the thermal stability of silicone products is high, and the chemical bonds of silicone molecules continue to split and not decompose at high temperature (or irradiation). Silicone can not only withstand high temperature, but also low temperature. It can be used in a wide temperature range. Both chemical and physical mechanical properties vary little with temperature.


Weatherability


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


Electrical Insulation Performance


Silicone products all have good electrical insulation properties. Their dielectric loss, voltage resistance, arc resistance, corona resistance, volume resistance coefficient and surface resistance coefficient are among the top insulating materials, and their electrical properties are little affected by temperature and frequency. Therefore, they are a kind of stable electrical insulation materials, which are widely used in the electronic and electrical industries. In addition to excellent heat resistance, organosilicon also has excellent water repellency, which is the guarantee of high reliability of electrical equipment in wet condition.


Biological characteristics


Bioactive organosilicon is a necessary nutrient for human body. Organosilicon is an important element that constitutes human tissues and participates in metabolism. It exists in every cell of the human body as a support for cell construction and helps other important substances such as magnesium, phosphorus and calcium to absorb. The human body can only continuously obtain organosilicon through food.


Scientists believe that organosilicon exists mainly in three forms in the human body:


Soluble organosilicon accounts for 10% of the weight.


Thirty percent of them exist in various cell matrices.


60% is used to synthesize proteins, which means that we need a fairly high amount of silicone every day.


If you want to remain young for five years, 10 years or even 30 years, it is particularly important to take 20-30 mg of organosilicon every day.


Low surface tension and low surface energy


The main chain of organosilicon is very flexible. The intermolecular force of organosilicon is much weaker than that of hydrocarbons. Therefore, the viscosity of organosilicon is lower than that of hydrocarbons with the same molecular weight, the surface tension is weaker, the surface energy is smaller and the film forming ability is stronger. This low surface tension and low surface energy are the main reasons for its application in many ways: hydrophobic, defoaming, foam stabilization, anti sticking, lubrication, polishing and other excellent properties.


From Silicone Public