Abstract :

Akwaibom (Iba Oku clay) was employed as a pigment extender to produce alkyd paints with mild steel-friendly anti-corrosive properties. 0.075 mm of this clay particles were employed as extender contents ranging from 0 to 80.0 weight percent. Reference alkyd paint was produced with titanium dioxide, and xylene. Main ingredients found in this clay in wt.%, where silica (58.19), alumina (35.35), titanium dioxide (2.60), and traces of other metallic oxides. From the study, this clay was stable to heat and chemical medium. Products painted with the sample paint had satisfactory surface and complete drying times with the best complete drying time gotten at 220 minutes for 80 wt.% clay. The paint film thickness was between 0.10 and 0.15 mm, showing abilities to give weather-resistant barriers and good impact resistance. The quantity of clay in the dry paint film increased the hardness of the paint film giving a maximum pencil hardness of 5H for 60 and 80 wt.% clay. General adhesion of the paint dry coatings on mild steel surfaces was in the range of 3.0 to 25.0%. Neither blistering, nor serious paint defects were seen on immersion into 2.5% NaCl, except minor color changes due to anti-corrosive properties inherent in it. This is in contrast to the performance at 2.5% for H2SO4, where some notable paint flaws occurred while 2.5% Na2CO3 was generally satisfactory. This study gives value to this clay as an extender pigment suitable in the formulation of paints for the protection of mild steel in saline conditions.