Banca de QUALIFICAÇÃO: CLÁUDIO JOSÉ GALDINO DA SILVA JUNIOR

NATURAL DYEING OF BACTERIAL CELLULOSE MEMBRANES FOR APPLICATION IN THE TEXTILE INDUSTRY

fashion; design; biotechnology; sustainable clothing; bacterial cellulose; natural dyes;

Fashion's consumerism has been associated with excessive purchase and disposal of clothing and accessories by capitalist society. This has been an issue due to the expansion of globalization especially at the beginning of the 21st century. The involvement of new designers in the apparel industry has contributed to create a desire for new and more conscious trends. However, the accelerated pace of transitions between collections have been making fashion increasingly frivolous with the capacity of generating the consumer's interest in new products at an accelerated pace, accompanied by an increase in their disposal. Thus, studies have been carried out on the sustainable development of textile materials for their use in the fashion industry. The objective of this project was to evaluate the potential of a water-resistant vegan leather produced with a Bacterial Cellulose (BC) biopolymer dyed with natural colorants, in addition to conducting a study on the future of fashion and biotextiles. The BC production process involves the fermentation of a Camellia sinensis-based media by a symbiotic culture of bacteria and yeast (SCOBY). The dyeing process involves the use of natural plant-based dyes extracted from Allium cepa L., Punica granatum and Eucalyptus globulus L. At this stage of this thesis, the BC membranes were blended and reassembled to produce a uniform surface with a constant thickness of 0.10 cm. The samples were waterproofed with Melaleuca alternifolia essential oil and Copernicia prunifera wax. The properties and characteristics of the biotechnological vegan leather were analyzed using Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), flexibility and mechanical tests, as well as by the determination of the water contact angle and sorption index (s). The results confirmed that the biomaterial has high tensile strength (with a maximum: 247.21±16.52 N) and high flexibility, being able to be folded more than 100 times at the same point without any breakage or cracks. The contact angle with water was 83.96°, indicating a low interaction of water with the biotextile. The results of the present study demonstrate the potential of BC for the development of innovative, durable, vegan and water-resistant fashion products. Other applications of microbial cellulose in various industrial sectors are underway to prove its versatility and importance for the market.