Abstract: The invention relates to thermoplastic cross-linked polymer compound with thermally reversible urethane crosslinkages comprising the following essential components a) to d): a) a thermoplastic polymer component with saturated molecular main chain: b) a component containing isocyanate group(s), either attached to the polymer chain or being present in mobile form in the polymer matrix; c) a component containing hydroxyl group(s) either attached to the polymer chain or being present in mobile form in the polymer matrix; d) a catalyst package promoting the reversible formation and thermal dissociation of urethane bonds, characterized in that at least one of the components b) and c) is attached to the polymer chain and at least one of the additives present in the compound is multi-functional, playing a role in more than one, functionally independent processes.