Multilayer structure, intended for the transport, distribution and storage of
hydrogen, comprising, from the inside out, at least one sealing layer (1) and at least one composite reinforcement layer (2), said innermost composite reinforcement layer being wound around said outermost adjacent sealing layer (1), said sealing
layers being made of a composition comprising predominantly: at least one aliphatic
polyamide thermoplastic polymer P1i, i=1 to n, n being the number of sealing
layers, semi-crystalline having a Tf, as measured according to ISO 11357-3: 2013, greater than 200°C, excluding a
polyether block amide (PEBA), said
polyamide thermoplastic polymer being a
polyamide having an average number of carbon atoms per
nitrogen atom of 7 to 9, up to 30% by weight of shock modifier relative to the total weight of the composition, up to 1,5% by weight of
plasticizer relative to the total weight of the composition, said composition being free of nucleating agent, said at least one
thermoplastic polyamide
polymer of each sealing layer being either identical or different, and at least one of said composite reinforcement
layers being made of a fibrous material in the form of continuous fibers impregnated by a composition comprising predominantly at least one P2j polymer, said structure being free of a polyamide polymer layer, said polyamide polymer layer being the outermost layer and adjacent to the outermost composite reinforcement layer.