Abstract: A process for crosslinking a polymer, includes at least the following steps: a) providing a polymer; b) providing a crosslinking agent; c) carrying out one or more crosslinking steps in the presence of the polymer and the crosslinking agent; d) obtaining a crosslinked polymer; wherein the crosslinking step or each of the crosslinking steps is carried out at constant temperature or at a temperature that varies linearly or in a stepwise manner, the constant or variable temperature being less than or equal to 15° C., and in that the crosslinking step c) has a duration of between 3 and 72 hours.