Executive Summary : | Natural leather products are greatly favoured by customers due to its durability, exquisite hand feeling with excellent physical and mechanical properties as well as outstanding comfort. During prolonged usage, leathers are certainly suffering from physical damages, the scratches occurring on the surfaces will harm the surface grain structures and reduce the lifespan of the materials. Leather products are likely garments, automotive upholstery (Car seat), furniture upholstery (Sofa, Chairs) is found to be durable but their surfaces and its coatings are not. Therefore, in order to maintains its durability, the recent research has been focused on the generation of self-repair polymers for generation of self-repairable leathers. In general, self-healing polymer coatings are a class of material coating that have the ability to repair micro-scale damage in the coating and restore the passive state of the many substrates. Such coating allows materials to repair themselves automatically after sustaining damage. The self-healing potentials of materials depend strongly on their intrinsic and extrinsic properties. Intrinsic self-healing materials achieve repair through the inherent reversibility of chemical bonds and physical interaction between the damaged interfaces, and extrinsic self-healing materials repair themselves via intentionally pre-embedded healing agents. Amongst self-healing polymers, healable polyurethane is one of the systems that exhibits repairing via supramolecular interaction. Therefore, the proposal aimed to develop water soluble polyurethane-based silica networks that exhibit self-repairing characteristics upon exposure to ultraviolet light/ natural sunlight. The polymeric network consists of an alkene oxide-substituted polysaccharides precursor incorporated into a polyurethane- silica hybrid composite network. Upon mechanical damage of the network, alkene oxide rings open to create two reactive ends. When exposed to ultraviolet light, polysaccharides chain scission occurs, which forms crosslinks with the reactive alkene oxide ends, thus repairing the network. Main advantage of this material lies in capable of repairing themselves in less than an hour and can be used in leather coating applications in aqueous medium. Therefore, the polyurethane-silica based self-repair polymers could be employed as the safety shield of leather especially automotive upholstery and garments where the chances of scratches are more. The novelty of the proposed work lies in the preparation aqueous-based self-healing polymers suitable for leather coating application. Designing of polymers is majorly based on the better binding with the leather surface. Sunlight assisted self-healing has the potential to revolutionize the leather industry by producing highly surface durable leathers. To the best of our knowledge, the development of sunlight driven self-repairable leathers has not been done and reported yet. |