Volatile Organic Compounds (VOCs) Quantities Emitted by Silicones

Silicone extrusions are popular products when it comes to applications where outgassing is an important factor. This includes sealing applications in the lighting equipment, laboratory controlled chambers and incubators or even building of aircrafts. On this article we will further explore the science of silicone towards outgassing to see how we can reduce the level of emission.

Since as the rate of outgassing increases at higher temperatures, the outgassing can be reduced through the process of post-curing. This is achieved through diffusion and evaporation, resulting in removal of the volatiles from the cross-linked silicone rubber at extreme temperatures. On the contrary in a situation where outgassing is to be avoided and the volatiles are not reduced to allowable levels, and then silicone products are exposed to hot temperatures with poor ventilation, it can lead to in-field failure. It might be a leakage of lighting enclosure or biospecimen destruction in an incubator.

Other method of reducing VOCs is by custom-formulating the raw mix used to make silicone extrusions. This including selecting the base material that meets the outgassing requirements and also the type of catalyst used to cure the silicone. Incidentally, measurements of weight being lost are generally used as an indicator of outgassing in elastomers (parts per million, aka ppm). Specific values for vacuum weight loss depend on the elastomer and sample conditioning. Generally, weight loss of less than %0.1 (1000ppm) is considered to be extremely low VOC levels. Below is the information from a study for outgassing of silicone based on different types of catalysts:

Our experience with our product used for the most delicate applications with regards to outgassing has also proved that silicones are the appropriate sealing materials for minimal outgassing. Also the amount of VOC depends on the type of silicone material, preparation as well as post-processing and comparative data, is available when the product material and manufacturing processes are fully defined.

To find out more about Jehbco’s solid silicone rubber and its outgassing component, read the website and Contact Us right here.