Method for preparing a material formed from arborescent-branched molecules comprising associative groups

Method for preparing a material formed from arborescent-branched molecules comprising associative groups comprising the following successive steps:

• (a) the reaction of at least one compound that is at least trifunctional (A) bearing first and second functions with at least one compound (B) that is at least bifunctional, the functions of which are capable of reacting with the first functions of compound (A), preferably in a number ratio of the functions of compound (B) to the sum of the first functions of compound (A) ranging from 0.1 to 0.8 and preferably from 0.3 to 0.8;
• (b) the reaction of the compound or compounds obtained in step (a) with at least one compound (C) bearing, on the one hand, at least one reactive group capable of reacting with the second functions of (A) and, on the other hand, at least one associative group,
• said compound (C) corresponding to formula (C1), (C2) or (C3):
• where
• R denotes a unit containing at least one primary or secondary amine or alcohol group,
• R′ denotes a hydrogen atom,
• A denotes an oxygen or sulphur atom or an —NH group, preferably an oxygen atom.