Rubber-Lexicon
Silicon rubber (VMQ)
Silicon elastomers are distinguished from other elastomers through the fact that they are not purely organic compounds. Instead of carbon polymer chains of the normal elastomers, the silicon polymer chain alternatively consists of silicium and oxygen atoms (siloxane). Silicon rubbers are processed as solid rubber and usually peroxidically cross-linked or processed as liquid rubber and usually cross-linked by addition.
Silicone elastomers have a good resistance to heat, ozone and ageing as well as a good resistance to chemicals. The mechanical characteristics however are rather below those of the other elastomers. Silicone rubbers are characterised through the almost unchanged mechanical characteristics over the entire temperature range of -60°C to +180°C. In order to obtain optimal heat resistance and a low pressure permanent set, a post tempering is necessary in many cases.
VMQ is for Shore-hardness Shore A 30-85 available.
Areas of application: Seals for deep freezers, stoves, drying cabinets, windows and cabin doors of airplanes, shaft seals, O rings, shutdown mats, medical-technical items, electric isolators.