Multilayer Polymer Structure Multilayer structure comprising at least one couple (L1-L2) of adjacent layers (L1) and (L2), wherein layer (L1) comprises at least one polymer composition (C1) comprising a grafted fluoropolymer material (M1) consisting of N1 grafted fluoropolymer(s) (P1), said polymer(s) (P1) obtained by a process comprising grafting onto an ungrafted fluoropolymer (U1) at least one grafting agent (G1) chosen from ethylenically unsaturated carboxy acids, their esters, their anhydrides and their salts, layer (L2) comprises at least one polymer composition (C2) comprising at least one impact modifier (I2) and a semi-crystalline aromatic polyamide material (M2) consisting of N2 semi-crystalline aromatic polyamide polymer(s) (P2), and the average melting temperature (Tav,1) of material (M1) differs by at most 45° C. from the average melting temperature (Tav,2) of material (M2), Nj being the number of polymer(s) (Pj) of material (Mj), Nj>1, Tav,j being equal to formula (T) wi,j being the weight amount of the ith polymer (Pj) of material (Mj), Ti,j being the melting temperature of the ith polymer (Pj) of material (Mj), Wj being the total weight amount of material (Mj), for j=1 and for j=2. Process for manufacturing the above multilayer structure, which comprises co-extruding polymer compositions (C1) and (C2), so as to obtain couple (L1-L2) of adjacent layers (T1) and (T2). Shaped article comprising the above multilayer structure, and process for manufacturing it. ( ∑ i = 1 N j  w i , j  T i , j ) / W j ( 1 )