The study of epoxy polyamide and polyvinyl resins as corrosion protective coatings on low carbon steel

The corrosion resistance of two commonly used protective coatings (epoxy polyamide and polyvinyl resins) in the Niger Delta area of Nigeria has been assessed. The coatings on low carbon steel were subjected to varying conditions of pH, temperature and exposure time and the corrosion rates calculated. At a pH of 2, 3, 4, 5 and 6 the corresponding calculated corrosion rates in mpy for epoxy polyamide resin were 0.677, 0.660, 0.392, 0.345 and 0.336 respectively and that for polyvinyl resin were 0.345, 0.336, 0.315, 0.298 and 0.272 respectively. At temperatures of 30oC, 40oC, 50oC, 60oC and 70oC, the corresponding calculated corrosion rates in mpy for epoxy polyamide resin were 0.169, 0.399, 0.572, 0.856 and 0.971 respectively and that for polyvinyl resin were 0.112, 0.227, 0.402, 0.572 and 0.741 respectively. At an exposure time in hours of 672, 1008, 1344, 1680 and 2016, the corresponding calculated corrosion rates in mpy of epoxy polyamide resin were 0.014, 0.018, 0.034, 0.044 and 0.059 respectively and that for polyvinyl resin were 0.0001, 0.009, 0.021, 0.44 and 0.046 respectively. The results showed polyvinyl resin to have a better coating performance than epoxy polyamide resin. KEY WORDS: Corrosion, coatings, temperature, polyamide, polyvinyl. Global Jnl Pure & Applied Sciences Vol.10(2) 2004: 301-30