Abstract: The invention relates to a bonding agent for PVDF, containing alkyl (alkyl)acrylate units and units bearing a carboxylic acid functional group. This bonding agent, containing PVDF, forms a barrier to hydrocarbons. The invention also relates to the material including the present bonding agent, especially petrol pipes including polyamide and the present bonding agent, in conjunction with PVDF.

Abstract: An immiscible polymer system is disclosed, said system itself ecomprising a stable mixture of polymers that are individually miscible with the polymers to be compatibilized. The compositions consisting of this polymer mixture may be obtained by extrusion.

Abstract: The present invention relates to antistatic and adherent compositions based on polyamide, which can be employed especially for the manufacture of composite materials and articles, such as multilayer pipes and/or conduits for conveying and/or storing hydrocarbons. The compositions contain carbon black and are employed for the production of pipes, containers and drums including:an inner layer in contact with the hydrocarbons, based on the said antistatic and adherent composition,a middle layer made of fluoropolymer, preferably of polyvinylidene fluoride, andan outer layer of polyamide,these layers being bonded to each other respectively by layers of adhesive binder. The invention also relates to a process for preparing these items.