The invention relates to a flexible pipe comprising at least one polymer layer, and at least one armouring layer unbounded to said polymer layer, wherein at least one polymer layer is a cationic clay containing polymer layer of a polymer material comprising a polymer matrix and from about 0.1 to about 5% by weight of at least one cationic clay silicate. Preferred cationic clay silicates comprise kaolinite; smectite; lllite; chlorite; and synthetic cationic clays. The cationic clay silicate may e.g. be an organo-cationic clay. The cationic clay silicate may preferably be exfoliated and/or intercalated in the polymer matrix. The polymer layer may preferably comprise an inner liner, a thermally insulating layer, an anti-wear layer and/or an outer sheath or a sub-layer thereof.