El propósito de esta tesis doctoral fue evaluar la influencia de los diferentes procesos de gestión de residuos, tales como la valorización material, energética y biológica de dos poliésteres clave de la industria del embalaje: el actual no-renovable poli (tereftalato de etileno) (PET) y el potencial candidato para sustituirlo en un futuro próximo, la polilactida (PLA) de base renovable. Se utilizaron diversas plantas piloto para simular las condiciones de la degradación sufrida por PET y PLA en el reciclado mecánico, la pirólisis, la combustión y el enterramiento en suelo. Los cambios fueron monitorizados por calorimetría diferencial de barrido (DSC), análisis dinámico-mecánico-térmico (DMTA), análisis termogravimétrico (TGA), espectrometría infrarroja con transformada de Fourier (FTIR), espectroscopia de correlación 2D-IR para el análisis de gases (EGA), espectrometría de masas MALDI-TOF, microscopía electrónica de barrido (SEM), índice de fluidez de masa fundida (MFR), ensayos de tracción e impacto Charpy y viscosimetría. Se han propuesto, desarrollado y aplicado diversas estrategias y procedimientos analíticos para establecer parámetros fiables para ser utilizados como indicadores de la degradación y por tanto controlar la influencia de cada proceso de valorización en la calidad del material. El comportamiento de PET y PLA reciclados mecánicamente se evaluó en base a sus propiedades químicas, microestructurales, mecánicas y térmicas. Se observó una pérdida general de prestaciones de PET y PLA reprocesado una vez y dos veces, respectivamente. Además, las propiedades de los materiales reciclados de PLA fueron mejores en términos relativos a los productos reciclados de PET. Las descomposiciones térmica y termo-oxidativa causadas por los procesos de pirolisis y combustión se evaluaron sobre la estabilidad térmica, gases emitidos y cinéticas de descomposición. Se destaca el uso de la combustión controlada para ambos polímeros, ya que se necesita menos energía para iniciar la descomposición, y la mezcla de gases que se desprenden es más homogénea. / Badía Valiente, JD. (2011). Strategies and analytical procedures for a sustainable plastic waste management. An application to poly (ethylene terephthalate) and polylactide in the packaging sector [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/12890

Plasma-based surface modifications offer many interesting possibilities for the production of high value-added polymeric materials. In this work, different plasma-based synthetic concepts were employed to endow poly(ethylene terephthalate) (PET) fabrics with accessible amine functionalities. These concepts were compared to find out the appropriate engineering methods, which can be further accepted by textile industries to overcome the limited reactivity of PET fabric surfaces, while the bulk characteristics are kept unaffected. Amine functionalities were introduced onto the surface of PET fabrics using either low-pressure ammonia plasma treatment or coating oxygen plasma-treated PET fabric with cationic polyelectrolytes. Two different cationic polyelectrolytes were used in this study namely poly(diallyldimethylammonium chloride) as an example of strong polyelectrolytes and poly(vinyl amine-co-vinyl amide) as an example of weak polyelectrolytes. The modified surfaces were characterized by a combination of various surface-sensitive techniques such as X-ray photoelectron spectroscopy (XPS), electrokinetic measurements and time-dependent contact angle measurements. Furthermore, the amine functionalities introduced by different surface modifications were used for the subsequent immobilization of various classes of anionic dyes to evaluate the efficiency of different surface modifications. Color strength (K/S) and fastness measurements of colored fabrics were also explored. Their results can be taken as a measure of the extent of the interaction between different modified surfaces and anionic dyes. Finally, it was demonstrated that anchoring poly(vinyl amine-co-vinyl amide) layer onto PET fabric surfaces modified with low-pressure oxygen plasma is an efficient approach to improve coloration behavior and to overcome different problems related to PET fabrics coloration, such as coloration of PET/wool blend fabric with a single class of dyes. This is a crucial step towards the substrate independent surface coloration, which becomes dependent on the properties of the top layer rather than chemical structure of the fibers.

Plasma-based surface modifications offer many interesting possibilities for the production of high value-added polymeric materials. In this work, different plasma-based synthetic concepts were employed to endow poly(ethylene terephthalate) (PET) fabrics with accessible amine functionalities. These concepts were compared to find out the appropriate engineering methods, which can be further accepted by textile industries to overcome the limited reactivity of PET fabric surfaces, while the bulk characteristics are kept unaffected. Amine functionalities were introduced onto the surface of PET fabrics using either low-pressure ammonia plasma treatment or coating oxygen plasma-treated PET fabric with cationic polyelectrolytes. Two different cationic polyelectrolytes were used in this study namely poly(diallyldimethylammonium chloride) as an example of strong polyelectrolytes and poly(vinyl amine-co-vinyl amide) as an example of weak polyelectrolytes. The modified surfaces were characterized by a combination of various surface-sensitive techniques such as X-ray photoelectron spectroscopy (XPS), electrokinetic measurements and time-dependent contact angle measurements. Furthermore, the amine functionalities introduced by different surface modifications were used for the subsequent immobilization of various classes of anionic dyes to evaluate the efficiency of different surface modifications. Color strength (K/S) and fastness measurements of colored fabrics were also explored. Their results can be taken as a measure of the extent of the interaction between different modified surfaces and anionic dyes. Finally, it was demonstrated that anchoring poly(vinyl amine-co-vinyl amide) layer onto PET fabric surfaces modified with low-pressure oxygen plasma is an efficient approach to improve coloration behavior and to overcome different problems related to PET fabrics coloration, such as coloration of PET/wool blend fabric with a single class of dyes. This is a crucial step towards the substrate independent surface coloration, which becomes dependent on the properties of the top layer rather than chemical structure of the fibers.