Orevac 18732 Modified polypropylene Arkema OREVAC PP is modified polyethylene which, when molten, has excellent adhesive properties to various substrates and is designed to bond dissimilar materials in coextrusion multilayers. OREVAC 18732 is designed for use in applications where both its adhesive properties and the mechanical and heat resistance properties of polypropylene can be exploited. OREVAC 18732 is designed to be used as tie-layer in 3-layer coatings (epoxy primer/adhesive/polypropylene) for external pipe protection. It is important that the polymer is bonded chemically with the epoxy primer. Modified polypropylene. Used as tie-layer in 3-layer coatings (epoxy primer/adhesive/polypropylene) for external pipe protection. Possesses very good adhesive properties to various substrates and mechanical properties.