Sustainable Coatings Composed of Bio-Binders and Organic/Inorganic Waste-Derived Colorants

The textile industry relies heavily on the use of conventional chemicals and finishing processes, including fossil fuel-derived polymers that improve textile properties such as softness, strength, water repellency and antimicrobial characteristics. However, growing environmental awareness and concerns towards waste production combined with technological innovations are driving a transition towards the use of more sustainable substances, such as bio-based polymers. The latter comprise materials that are produced partially or entirely from biomass and includes cellulose, chitosan, starches and lignin that are used as environmentally friendly substitutes for synthetic textile finishing agents. The advantage of using these materials is their enhanced biodegradability and reduced carbon footprint compared to traditional materials. This thesis presents the research work carried out during a four-months internship at CITEVE company. The aim of the study was to investigate the use of bovine collagen as a bio-binder in combination with organic and inorganic colorants derived from agricultural waste. The employed agricultural residues were rice husk, wine pruning, wine bagasse, almond shell and chestnut shell. Different formulations were investigated to identify the most suitable coating for cotton fabrics. A baseline formulation, previously tested from the company, was used as benchmark and the content of selected additives and agricultural waste powders in different sizes was adjusted to identify the optimized composition. Subsequently, each obtained paste was applied to cotton fabrics through a coating process. Finally, the most promising coated samples were characterized by quality control tests, such as abrasion resistance and color fastness. Among the investigated formulations, one showed the most promising results, with particularly good performance achieved for the formulations integrating almond shell particles. It can be concluded that the chosen formulation represents a solid basis for further development and the obtained results demonstrate the potential for collagen-based coatings. Additional testing and optimization could be carried out in future studies to further improve the coating performance.