Aging properties and resistance to various media

Aging and heat resistance
Baypren^® vulcanizates display excellent aging resistance, especially those with an optimized antioxidant content. They neither soften nor harden at high temperatures or over long periods of stressing and remain elastic and serviceable. The heat resistance of Baypren^® vulcanizates is considerably better than that of natural rubber vulcanizates. It corresponds roughly to the heat resistance of nitrile rubber.

Weathering and ozone resistance
While vulcanizates produced from many other rubber types tend to crack and harden relatively quickly and degrade when exposed to weathering and/or ozone, suitably formulated Baypren^® vulcanizates do not exhibit any significant deterioration, even after many years of exposure to atmospheric influences such as light, rain, industrial gases and oxygen. By extrapolating the change in mechanical properties after many years of weathering in an ozone-rich atmosphere, it can be concluded, on the basis of current technology, that technical rubber goods made of Baypren^® can be expected to display sufficient elasticity for the majority of static applications (for example structural profiles) after more than 50 years.

Resistance to water and chemicals
By employing specially formulated compounds, it is possible to obtain Baypren^® vulcanizates that are resistant to water, acids, alkaline solutions and a large number of industrial chemicals. Resistance to hydrocarbons Baypren^® vulcanizates possess sufficient resistance to mineral oils to make them suitable for many applications. Their resistance to swelling by mineral oils improves as the naphthenic and, in particular, the aliphatic content of the oil rises. They cannot match the very high swelling resistance to hydrocarbons of similarly formulated nitrile rubber vulcanizates, but their swelling resistance is considerably better than that of vulcanizates based on styrene-butadiene rubber, natural rubber or ethylenepropylene rubber.

Resistance to fungi and bacteria
Items made of rubber that are in contact with soil for long periods of time are susceptible to attack by soilborne bacteria and fungi. In the long term, this can lead to underground cables, for example, being destroyed. In contrast to the majority of other rubber types, Baypren^®
displays marked resistance to these microorganisms. This resistance can be enhanced still further through compound formulation.