The main use of the experts to explain the characteristics of silicone rubber
The main use of the experts to explain the characteristics of silicone rubber
Silicone rubber products are methyl vinyl silicone rubber as the base rubber, the presence of a variety of digging materials (reinforcing agent, heat-resistant agent, modifier, etc.) by mixing, book through, filtration, reduce sulfur, molding, extrusion, bonding and other consumption process. Vulcanized rubber products have the following characteristics:
(1) under high temperature resistance: under 200 degrees Celsius can be temporarily used, is still under -60;
(2) electrical insulation performance: the dielectric properties of silicone rubber is excellent, especially the dielectric properties of the new year's Eve at the lower temperature, the dielectric strength is almost not affected by the temperature in the range of 20-200.
(3) good weather resistance, ozone resistance and resistance to ultraviolet radiation performance, by using temporary room is no charge for cracking. Generally feel that the silicone rubber can be used in the room for more than 20 years.
(4) the lower temperature shrinkage of the inferior show permanent deformation.
(5) the deterioration of the poor performance, easy molding and other bad side, can be through the process of extrusion hot air curing molding, molding, molding, and so on.
Because the silicon rubber product with bad show the comprehensive performance war carrier show technical and economic results, have been in aviation, space, book, electrical appliances, electronics, instrumentation, automotive, machinery, metallurgy, chemical industry, medical health, as usual in a range of paste various heart has been widely used.
Silicone rubber identity
Silica gel SiO2, xH2O, or nH2O mSiO2, also known as silica gel or silica gel. Silica gel into a colorless transparent or milky red particles. The dew point is about 3 ~ 7%. Porous machine with closed. The strong adsorption, dry can reach 40% center. Mainly used for gas monotone, gas absorption, liquid dehydration, catalyst, catalyst carrier and gas phase chromatography to clarify that reagent, TLC analysis reagent, column chromatography dig material. In order to indicate that the size of the water water Ze, market to sell the allochroic silicagel is silicic acid gel with cobalt chloride solution soaking, monotonous activation of a single scheduling. With the sodium silicate solution (water glass) with hydrochloric acid or dilute sulfuric acid reaction, by gel, washing, drying, drying made.
Characteristics of silica gel
Silicone rubber powder is also by SI-O (molecular oxygen) into the closed machine key chain. SI-O bond is 443.5KJ/MOL, than the C-C bond energy (355KJ/MOL) under a lot, and the fruit of its molecular machine closed, making the silicone rubber than other general rubber with better heat resistance, electrical insulation, chemical stability, etc..
Model of silicon rubber is scattered two methyl siloxane, with a spiral configuration of molecules, the intermolecular force is small, fruit this is the resilience of the bad show, at the same time that back spiral formaldehyde can free torsion, fruit the silicone rubber with allocation table properties, such as hydrophobicity and anti sticking.
1. Heat resistance: silicone rubber than ordinary rubber has good heat-resistant, is 150 degrees almost permanent use and performance change; can be in 200 degrees as the 10000 hours; is 350 degrees, can also make use of the period of time. Widely used in heat resistant place: hot water bottle with a thin ring pressure cooker ring heat foot handle.
2 heat resistance: the general rubber surface is -20 degrees ~-30 degrees, that is, silicone rubber is ~-70 degrees -60 degrees still have better flexibility, some special with a round of silicone rubber can accept the high temperature. High temperature dilute.
3. Weatherability: general rubber is corona discharge are dead ozone do rapid degradation, and silicone rubber is not affected by ozone. And less work women are purple center line war other climate conditions, its physical properties are only small change. The thin and open materials used in the household.
4: the electrical properties of silicone rubber with temperature and frequency range of the resistivity is very wide and is its resistance stability. At the same time, silicone rubber has good resistance to pressure and corona discharge arc discharge. Lower pressure parts, lower pressure cap of TV set, electric appliance integral component.
5 electrical conductivity: when the scene conductive material (such as carbon black), silicone rubber will have conductive keyboard conductive contact surface, electric heating component parts, anti static parts, under pressure cable shielding, medical treatment of conductive film.
6 thermal conductivity: when the presence of certain heat conductive materials, silicone rubber will have a heat conductive heat sink, heat conductive thin pad, copy machine, fax machine heat transfer roller.
7. The radiation resistance: dew phenyl silicone rubber radiation resistant Danian evening Nianye forward to make electricity cables, nuclear power plant with adjacent.
8 flame retardant: silicone rubber their own fuel, but the increase or decrease of a large number of anti combustion agent, it will have a fire resistance and self extinguishing properties; and fruit silicone rubber without dew organic halide, fruit this combustion without smoke or release gas. A wide variety of waterproof place.
9 air permeability: silicone rubber film is better than general rubber and plastic film. The other characteristic is that it has a strong selectivity to the good air permeability. Gas exchange membrane medical supplies, human organ.