Are there any substances which polyurethane does not adhere to?
Polyurethane foam can be sprayed on a wide variety of materials and substrates as long as the substrate surface is clean and / or prepared appropriately before application.
Metals may require cleaning and use of a primer before installing polyurethane insulation. Plastic materials may present specific needs.
In particular, the polyurethane material does not adhere to polyethylene and polypropylene.