The invention relates to a multilayer laminate (10) a sandwich structure made up of a first layer (11) made of a blend of polymers comprising polyethylene terephthalate and a material selected from low-density polyethylene, medium density polyethylene, high density polyethylene and polypropylene, a second layer (12) made of said blend of polymers and a third layer (13) sandwiched between said first and second layer (11, 12), said third layer (13) being made of said blend of polymers added with glass fibers. The polymer blend comprises from 6% to 14% by weight of low-density polyethylene, medium density polyethylene, high density polyethylene or polypropylene, the remainder being polyethylene terephthalate. Thanks to these features, the multilayer laminate of the invention features a corrosion resistance comparable to the corrosion resistance of fiberglass, but has superior mechanical properties allowing it to be employed in place of traditional fiberglass panels in the manufacturing of insulating panels for chemically aggressive environments.