Performance of anticorrosive coatings containing tripolyphosphate in aggresive environments

C. DEYÁ; A. DI SARLI; B. DEL AMO; R. ROMAGNOLI

INDUSTRIAL & ENGINEERING CHEMICAL RESEARCH

ACS Publications

Lugar: Austin; Año: 2008 vol. 47 p. 7038 - 7047

0888-5885

The objective of this research was to study the efficiency of calcium tripolyphosphate and zinc tripolyphosphate as anticorrosive pigments for paints in aggressive environments. Alkyd and epoxy paints, of the solvent-borne type, containing 30% by volume (v/v) of the pigment, were formulated. The pigment volume concentration/critical pigment volume concentration (PVC/CPVC) ratio was fixed at 0.8. In a second stage, water-borne paints containing 30% v/v of both tripolyphosphates and different PVC values (20 and 25%) were also formulated. Finally, standardized accelerated (salt spray and humidity chamber exposure) and electrochemical impedance spectroscopy (EIS) tests were used to assess the protective performance of the coatings. Analysis and interpretation of the experimental data show that both, calcium and zinc tripolyphosphates, inhibit corrosion of painted steel panels exposed to aggressive environments.