Based on silicon, an element derived from quartz. When creating this class of synthetic elastomers, pendant organic groups (such as methyl, phenyl and vinyl) are attached to silicone atoms. Adding these side chains can significantly alter the properties of the compound. Silicones have excellent heat, ozone and corona resistance, dielectric stability as well as resistance to many oils, chemicals and solvents. Like all elastomers, silicones possess the most flexible property at low temperatures. VMQ’s main weakness is low tensile strength, poor tear and wear resistance.
Cure system
Standard VMQ is usually peroxide cured. Platinum cured compounds offer more flexible properties and low volatile matter. Platinum cured silicones are usually used in medical systems or other required low volatile matter. Platinum cured silicones needs to be produced in clean rooms and the higher cost of platinum catalyzer makes them more expensive than regular peroxide cured ones.
Applications
- Often used in automotive systems like boots, oil filter valve, gasket in light etc
- Can be created using only “white list” ingredients as specified in 21.CFR 177.2600 for use in applications where elastomers will be in contact with food or beverages.
- Silicones can be submitted for approval by national sanitation foundation (NSF) for use in drinking water applications.
- Can be used in medical systems which require compliance to USP class VI.
General Information
- ASTM D 1418 Designation: Q, MQ, VMQ, PVMQ
- ISO/DIN 1629 Designation: Q, MQ, VMQ, PVMQ
- ASTM D2000 / SAE J 200 Codes: FC, FE, GE
- Standard Color(s): Rust
- Hardness Range: 25 to 90 Shore A
- Relative Cost: Medium-High
Service Temperatures
- Standard Low Temperature: -60°C / -76°F
- Standard High Temperature: 225°C / 437°F
- Special Compound Low Temperature: -100C / -150°F
- Special Compound High Temperature: 300°C / 572°F
| Performs well in | Does not Perform well in |
| Engine And transmission oil (mineral oils) | Concentrated acids and alkalis |
| Diluted salt solustions | Steam over 120° |
| Dry heat | Petroleum oils and fuel |
| Ozone, weather resistance | Ketones |