Please define "rubber". Is it Nitrile? Silicone? Viton? EPDM? What compound family is it in? The chemical compatability varies all over the map depending on the kind of rubber. It also depends on the temp and the concentration and the length of time in contact.
Parker Hannifin has a fairly extensive compatability chart for it's O-ring compounds on thier website that should give you a feel for which elastomer families that are compatable, but even then, compatability varies even among elastomers in the same family. For instance there are two major sub-groups in the viton family. One is MUCH more compatable with amines than the other is. The only real way to know for sure is testing.
