Fire Safety Science Digital Archive

Polyethylene flame-protected coatings are known to have good reliabilty, chemical resistance, insulating characteristics and prevent the metal form corrosion. In real use, however, there is a danger of damage or exfoliation of the coating resulting in a clearance between the coating and the metal. Atmosphere-induced washout of the coating components in this case stimulate their aggregation on the metal surface which may cause its corrosion. The possibility of reducitig corrosivity of the polyethylene coating containing the product of interaction of polyvinyl alcohol and methylphosphonic acid as a flame retadant additive by means of heterocyclic amine is studied in the paper. To stimulate the corrosive processes on a metal coating interface corrosive and polarisation measurements have been performed . It has been found that the degree of extract coating corrosion is determined by the concentration of methylphosphonic acid facilitating anode and cathode processes. The introduction of heterocyclic amine into a flame-retardant polyethylene promotes the retardation of both electrode processes, its ifluence on the anodic process being greater. The inhibiting effect of heterocyclic amine is supposed to be connected with the appearance of an additional absorption potential . In this case the effectiveness of heterocyclic amine decreases with pH icrease and this may be connected with the concurrence in the adsorption of hydroxyl and amine on the surface of iron. The conclusion of the possibilty to use the inhibitors of acid corrosion for the decrease of flame retardant coating corrosivity has been made.