Abstract: The invention relates to re-mouldable cross-linked resins and methods for preparing them. Provided is, inter alia, a re-mouldable cross-linked resin comprising polymer chains which are connected to one another via Diels-Alder adducts obtainable from a dienophile and a substituted furan wherein the substituted furan is obtainable by reacting an amino furan compound with a copolymer of carbon monoxide and an olefinically unsaturated compound.