Naslov
An application of dc and ac measurements in the study of beverage cans

Autori
Galić, Kata ; Murphy, Tom ; Ciković, Nada

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
International Society of Electrochemistry / The Electrochemical Society - : The Electrochemical Society (ECS), 1996, P6a-6

Skup
47th Annual Meeting

Mjesto i datum
Balatonfüred, Mađarska; Veszprém, Mađarska, 01.09.1996. - 06.09.1996

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
electrochemical methods; beverage cans; corrosion

Sažetak
Electrochemical methods are often used to study the protective characteristics of organic coatings on the metal substrate. DC and AC measurements were performed on lacquered tinplate and aluminium cans aimed for beverage packaging. As an electrolyte regular/diet Cola drinks (purged with CO_2 and thermostatically controlled at 25 ^oC) were used. For both DC and AC measurements a saturated calomel electrode (SCE) was employed as the reference electrode while the platinum grid was used as the counter electrode. Beverage can, with an area of 248 cm^2, represented a working electrode. DC measurements were carried out starting from the corrosion potential, firstly to the cathodic then to the anodic direction at scan rate of 10 mV/sec. The impedance measurements were performed starting also from the corrosion potential applying a sinusoidal signal of 5 mV amplitude over a frequency interval from 100 KHz to 5 Hz with five measurements per decade. Diet drinks showed to be slightly more aggressive as compared to regular drinks although the pH values for the regular ones were lower. Tinplate cans generally showed lower corrosion current values (0.21-0.496 nA cm^-2) compared with aluminium cans (0.19-1.768 nA cm^-2). The quantity of Al, Fe and Sn dissolved, after polarisation procedure, measured by AAS, was less then 0.1 ppm, which showed a good agreement with calculated values. The resistance of the coatings exceeded 10^8 ohm cm^2 and did not change much after seven days of being exposed to an electrolyte.

Izvorni jezik
Engleski

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