Crosslinking of siloxane elastomers

Silicones are widely used where elastomers come in contact with food and pharmaceuticals. Different curing methods can be applied for crosslinking this elastomer. Ageing tests clearly show that peroxide-cured silicone elastomers should be avoided in view of the fact that post-curing occurs if they are sterilized. This will result in a change in properties over time. Dicumyl peroxide is frequently used in the crosslinking of elastomer materials. Products that can be extracted from the elastomer after crosslinking with dicumyl peroxide include cumenalcohol and acetophenone. No organic compounds could be extracted from the platinum-cured elastomer. Peroxide-cured silicone elastomer shows an increase in Young's modulus by approx. 50% after 100 sterilizations whereas an elastomer cured with platinum shows a modulus that is almost constant. An addition of a curing system like platinum has the advantage of no peroxide handling. Furthermore, the platinum curing systems have the advantage of faster curing than peroxide curing. The uses of peroxide cured siloxane elastomers are based on old routines and the use of platinum-cured elastomers is recommended for the future. (C) 2002 Elsevier Science Ltd. All rights reserved.