We offer a broad range of organic peroxides for the crosslinking of silicone rubbers (Q-rubbers) under the well-known trademarks of Perkadox and Trigonox.
We distinguish between "general purpose" and "vinyl specific" crosslinking peroxides.
General purpose peroxides
General purpose peroxides can be used in all kind of silicone rubber compounds and are active at relatively low temperatures (90-120°C). As their decomposition products are acidic, post cure treatment is recommended, especially for thick sectioned articles.
Vinyl specific peroxides
- Dicumyl peroxide (Perkadox L)
- 2,5-Dimethyl-2,5-di(tert-butylperoxy)hexane (Trigonox 101)
For vinyl specific peroxide types, a very effective cure density is obtained in vinyl containing silicone rubber (150-170°C). As their decomposition products are not acidic, post cure treatment is relatively short or not necessary. Vinyl specific peroxides can be used in formulations containing carbon black and, in general, lead to better compression set properties as compared to general purpose crosslinked articles.
Formulated peroxides for optimal safety and processing
Our organic peroxides for curing silicon rubber are available in a wide range of phlegmatizers and carriers, and concentrations. Formulated peroxides are recommended. Not only because of safety considerations but also for reasons of handling, mixing, processing and final product properties. Silicone oil-based products have preference over peroxides on inert carriers such as silica or calcium carbonate in case transparency is of importance,.
Main peroxide selection criteria
Key criteria for selecting the right crosslinking peroxide include:
- Decomposition rate of the peroxide
- The type of peroxide and free radicals formed
- Processing and curing conditions
- Final product properties
Crosslinking performance of an organic peroxide is influenced by silicone rubber characteristics, such as polarity and number of reactive groups. In addition, compounding ingredients may adversely affect crosslink efficiency of organic peroxides.
Contact us to learn more about cure characteristics of our crosslinking peroxides, processing guidelines and the impact of certain compounding ingredients on silicon rubber curing.