Chemical processing of textile waste based on cellulosic and synthetic fibers
- Autores: Lorena Villar Blanco
- Directores de la Tesis: Pablo Breogán Sánchez Vázquez (dir. tes.), Begoña Gonzalez de Prado (dir. tes.)
- Lectura: En la Universidade de Vigo ( España ) en 2024
- Idioma: inglés
- Tribunal Calificador de la Tesis: Antje Potthast (presid.), Diego Moldes Moreira (secret.), Avinash Manian (voc.)
- Programa de doctorado: Programa Oficial de Doctorado en Ingeniería Química
- Materias:
- Enlaces
- Tesis en acceso abierto en: Investigo
- Resumen
Apparel production has shaped human communities since we have memories. Remarkable social and engineering breakthroughs such as the Silk Road or the Jacquard loom, precursor of computing hardware, have been triggered by textile markets and technologies. In the last years, as environmental concerns occupy a central role of the political agenda, the growing demand of textile products has led to a large production of waste which needs to be properly addressed. In this front, preventing the waste generation by extending the durability of apparel items and promoting their second-life needs to be supported by recycling technologies which contribute to reduce the use of virgin resources and the disposal of materials after their lifetime. The widespread use of garments made of natural and synthetic materials hampers their mechanical recycling which often downgrades the fiber quality. Thus, the preferred route for textile waste processing involves chemical treatments for the separation of textile blends and ulterior conversion of monomaterial streams into valuable products, ideally through fiber-to-fiber recycling.
In this context, I have focused on cellulose blends as this polymer represents 33% of the global market share of textile fibers (80% among the natural fibers) and thus, I have aimed to expand the knowledge on chemical technologies for textile recycling. With cellulose as the joint thread, I first studied the material properties of several cellulose sources and the solvent qualities influencing the dissolution process. Solvatochromic and viscometric analysis were performed to explore the polymer-solvent interactions and dissolution kinetics of cellulose was studied by cross-polarised microscopy taking advantage of its optical anisotropy (Villar, Cellulose, 2022). Then, I have focused on the separation of cellulose from polyester and elastane, as both synthetic polymers are frequently blended with cotton in the apparel industry hampering the recyclability of the natural stream. Catalytic-assisted hydrolysis of polyester and selective dissolution showed the capability of isolating cellulose from polycotton garments without causing major harm to the cellulose polymer chains (Villar, Fibers & Polymers, 2024). Also, as the presence of elastane in small proportions in cotton clothing has become very frequent hindering its recyclability, I have explored routes for elastane removal and subsequent conversion into MMCFs through dry-jet wet-spinning. Results proved the aminolytic decomposition of elastane occurs at conditions which preserve cellulose quality for its dissolution in superbase solvents rendering market-quality MMCFs (Villar, Biomacromolecules, 2023).
