MULTILAYER TUBULAR STRUCTURE HAVING IMPROVED RESISTANCE TO EXTRACTION IN BIOGASOLINE AND USE THEREOF

摘要

The present invention relates to a multilayer tubular structure (MLT) intended for the transport of a fluid, in particular gasoline, comprising at least one inner barrier layer (1) and at least one outer layer (2) located above the barrier layer, from the inside outwards. Is about The outer layer (2), or all of the layers (2) and other optional layers, located on the barrier layer comprises 0 to 5% of a plasticizer on average relative to the total weight of the composition of the outer layer (2), or All outer layers (2) located above the barrier layer comprise on average 0 to 5% of a plasticizer, said outer layer (2) being at least one polyamide, mostly of aliphatic type or of more than 75% of aliphatic units Wherein the aliphatic polyamide is: Polyamides represented by A having an average number of carbon atoms per nitrogen atom represented by C _A of 4 to 8.5, advantageously 4 to 7; Polyamide represented by B having an average number of carbon atoms per nitrogen atom represented by C _B of 7 to 10, advantageously 7.5 to 9.5; A polyamide represented by C having an average number of carbon atoms per nitrogen atom represented by C _C of 9 to 18, advantageously 10 to 18; When the outer layer 2 comprises at least three polyamides, at least one of the polyamides A, B and C has a clue which is excluded.