Studies on the Fabrication of Hydrophobic Coating Incorporating Bentonite Clay and its Effect on the Physical Properties of the Finished Leather

Abstract

One of the most important properties that can be added to leatherbased products is its ability to self clean as leather cannot be washed frequently like fabrics. A simple and direct method to achieve this is to introduce a hydrophobic coating on the top of the leather, which can minimize the adhesion of foreign particles and thereby improve stain resistance. Additionally, this also increases the economic, aesthetic and functional values of the material. Generally, a hydrophobic surface on the leather is created by coating a polymer based on fluorine or silicone, which has the tendency to repel the water droplets. In this paper, the effect of hydrophobic coating on the physical properties of the leathers was studied. It was observed that the hydrophobic coating had a positive effect on the rub fastness properties improving the rating of 3 to 4. Water vapor permeability of the FCP-A alone coated leather reduced from 8.7 to 4.4 mg/cm2 / hr in comparison to crust leather, owing to the sealing of pores on the grain surface due to the film formed by these polymers. However, incorporation of bentonite clay improved the water vapor permeability of the leathers from 3.4 to 12.9% in comparison to that of the FCP-A alone coated leathers owing to the pores created in the finish film. In addition, the contact angle of the leather surface was also increased from 98° to 121° due to the introduction of roughness induced by the clay particles. Hence, the proposed work can aid in the development of easy-care and smart leathers.