This invention relates to a polymeric membrane assembly which incorporates one or more layers of protective barrier films or protective barrier membrane layers to protect the susceptible polymer membrane from deterioration due to contact with water, oxygen or a combination of both. This invention also relates to a process for utilizing these polymeric membrane assemblies in separation processes involving hydrocarbon feedstreams. More particularly, but not by way of limitation, this invention relates to the use of these polymeric membrane assemblies in processes involving the separation of aromatics from a hydrocarbon based feedstream.