PVMQ Silicone - Material Profile
Updated: Jul 26, 2024
When it comes to Silicone O-rings and custom parts, most are familiar with standard VMQ Silicone or FVMQ Fluorosilicone. Less recognized is PVMQ Silicone, which is specifically formulated for extreme low temperature applications. Learn more about what makes PVMQ so special.
Common Types of Silicone
Silicone rubbers are silicon and oxygen (siloxane) based synthetic polymers. They are typically weather resistant and have versatile temperature ranges, but are limited by low abrasion resistance and tensile strength.
- MQ Silicone: Methyl Silicone (MQ) is a relatively simple form of silicone rubber. MQ is not frequently used to manufacture O-rings and custom rubber parts due to it's lacking mechanical properties, however it can be processed to improve its characteristics.
- VMQ Silicone: Vinyl Methyl Silicone (VMQ) is the most common form of silicone rubber. It has a versatile functional temperature range (typically around -60°C to 200°C) and good compression set, but still has mechanical limitations like poor abrasion resistance and relatively low tensile strength.
- FVMQ Silicone: Fluorosilicone (FVMQ) is as it sounds: A fluorinated silicone polymer. As with other fluorinated polymers, FVMQ's molecular structure has improved stability, lending the material improved chemical resistance over standard VMQ. Unfortunately, FVMQ also has a slightly reduced temperature range (typically around -60°C to 175°C).
- PVMQ Silicone: Phenyl Methyl Silicone (PVMQ) is a formulation of silicone that greatly improves the materials low temperature capabilities (typically around -80°C to 200°C).
What makes PVMQ Special
In standard MQ silicone, two methyl groups are bound to the siloxane backbone. This forms the primary structure of the polymer. With VMQ, some of the methyl groups in MQ are replaced with vinyl groups. One step further with PVMQ, some of the methyl groups in VMQ are replaced with phenyl groups.
As the blend ratio of phenyl groups are increased, the ratio of crystalized polymeric groups to amorphous polymeric groups is shifted, altering the materials physical properties and glass transition temperature. [1] The resulting PVMQ has a decreased tensile strength, modulus at 100%, and compression set. This equates to a mechanically worsened material. However, the low temperature performance of PVMQ is greatly improved by an extremely low glass transition temperature in relation to other silicone blends. [1]
Where can I get PVMQ parts?
With the request a quote page, you can get directly in contact with our team of specialists who will help get you the parts you need.
Sources:
[1] Lee, Jin Hyok, Jong Woo Bae, Myoung Chan Choi, Yu-Mi Yun, and Nam-Ju Jo. “Effect of Phenyl Vinyl Methyl Silicone (PVMQ) on Low Temperature Sealing Performance of Fluorosilicone Composites.” Elastomers and Composites 56, no. 4 (December 31, 2021): 209–16. doi:10.7473/EC.2021.56.4.209.
[2] Silicone rubber (Q, MQ, VMQ, PVMQ). (n.d.). Parker Hannifin Corporation. https://promo.parker.com/promotionsite/oring-ehandbook/us/en/ehome/Silicone-(Q,-MQ,-VMQ,-PVMQ)
