Investigation of the usability of acid regeneration plant by product hematite in castor oil based polyurethane adhesives as filling material

Polyurethane adhesives are widely used in various industries such as textile, construction and automotive. Fillers are added to polyurethane adhesives to reduce costs while improving the volume and bonding ability of the adhesives. Instead of lime and calcite, which are commonly used fillers, more economical alternatives are sought. In this study, acid regeneration plant by product hematite was chosen as a filler material because it can be reused in another sector as a by-product of iron and steel industry and also it would reduce costs compared to alternatives. Polyurethane adhesives were prepared using different amounts of lime, calcite and hematite. The adhesive mixtures were applied through a 21x25 mm bonding surface between a filter paper and metal plate already prepared with a size of 25x100 mm. Adhesion was not always observed in the samples where the adhesives were applied but it was broken off from the filter paper when it occurs. In order to examine the adhesion capability in more detail, the bonding surface area was reduced to 5x25 mm. Tensile test showed that the samples were again broken off from the filter paper. Secondly, the adhesives containing different amounts of fillers were applied through a 21x25 mm bonding surface between two metal plates and tensile tests were applied to these samples. The slippage performance of the adhesives glued with lime and hematite was 68.70% better than those glued with only calcite.