Technology is defined as "the application of scientific knowledge for practical purposes." Beyond this definition, technology embeds concepts such as problem-solving, optimization, and productivity. In all the human history, science and technology have been foundational pillars in the development of prosperous societies. Over the time, technology pushes its limits beyond what was once considered possible, an example is the integration of Generative Artificial Intelligence into everyday tasks. Thus, technology can be seen as a dynamic concept, capable of adapting its-self to global and societal needs. In light of pressing issues such as climate change and environmental challenges, modern society urgently requires a shift towards circular and sustainable practices. Among the various sectors that need an environmental transition, particular attentions have to be focused on scientific fields, due to its significant impact in every-day life. Globally, billions of tons of materials are produced annually. For instance, the global market of elastomer composites is expected to reach 2.7 billion units by 2025. Elastomer composites, particularly those used in tire manufacturing, are integral to various aspects of daily life, facilitating the movement of people and goods. Despite their essential role, these composites are predominantly made up of non-renewable sources, including fillers, coupling agents, vulcanization agents, and thermoset materials, all of which are oil-based and contribute to significant environmental impacts. Consequently, there is an urgent need to develop bio-based alternatives suitable for tire applications. This thesis explores the synthesis, characterization, and application of novel classes of bio-based molecules and materials for use in tire production, according to the basic principles of Green Chemistry and by using, where possible, bio-based building blocks for the preparation of new materials. Specifically, bio-based building blocks were used for the synthesis of thermoset materials, with the objective of replacing oil-derived Resorcinol and Hexamethoxymethylmelamine (HMMM) in the preparation of extra-reinforced composites. Then, lignocellulosic derivatives were used as the bio-based building blocks for synthesizing pyrrole compounds, aiming to replace conventional industrial, oil-based coupling agents. Sulfur, a by-product of petroleum refining, and pyrrole compounds were employed as novel substrates to create bio-circular poly(Sulfur-co-Pyrrole) copolymers, intended as substitutes for traditional oil-based crosslinking agents commonly used in rubber composites. Finally, chemical modification of Lignin with pyrrole compounds was conducted using Reactive Extrusion technique. The novel adducts were used for the preparation of rubber-to-textile adhesion applications and extra-reinforced rubber compounds. All the novel material were tested in the formulation and production of new rubber compounds. Finally, Lignin-Pyrrole adducts obtained by Reactive extrusion were used as reinforcing fillers for the preparation of high valuable thermoplastic materials based on Polybutylene adipate terephthalate (PBAT).
La tecnologia è definita come “l'applicazione della conoscenza scientifica per scopi pratici”. Al di là di questa definizione, la tecnologia racchiude in sé concetti quali la risoluzione di problemi, l'ottimizzazione e la produttività. In tutta la storia dell'umanità, la scienza e la tecnologia sono state pilastri fondamentali per lo sviluppo di società prospere. Nel corso del tempo, la tecnologia ha spinto i propri limiti oltre ciò che un tempo era considerato impossibile; un esempio è l'integrazione dell'intelligenza artificiale generativa nelle attività quotidiane. La tecnologia può quindi essere vista come un concetto dinamico, capace di adattarsi alle esigenze globali e della società. Alla luce di questioni pressanti come il cambiamento climatico e le sfide ambientali, la società moderna richiede urgentemente un passaggio a pratiche circolari e sostenibili. Tra i vari settori che necessitano di una transizione ambientale sostenibile, un'attenzione particolare deve essere rivolta ai campi scientifici, a causa del loro significativo impatto nella vita di tutti i giorni. A livello globale, ogni anno vengono prodotti miliardi di tonnellate di materiali. Ad esempio, si prevede che il mercato globale degli pneumatici raggiungerà i 2,7 miliardi di unità entro il 2025. I compositi elastomerici, ed in particolare quelli utilizzati nella produzione di pneumatici, sono parte integrante di vari aspetti della vita quotidiana, facilitando il movimento di persone e merci. Nonostante il loro ruolo essenziale, questi compositi sono costituiti prevalentemente da fonti non rinnovabili. Tra i maggiori esempi vi si ritrovano gli agenti rinforzanti, agenti di coupling, agenti vulcanizzanti e materiali termoindurenti. E' dunque necessario sviluppare alternative sintetiche per la produzione dei suddeti materiali, sfruttando, ove possibile, dei substrati di origine naturale con l'intento di sviluppare materiali adatti alle applicazioni in ambito di pneumatici. Pertanto, il presente progetto di Dottorato ha come obiettivi la sintesi, la caratterizzazione e l'applicazione di nuove famiglie di molecole e/o materiali di origine naturale e la valutazione della loro fattibilità nell'impiego durante la produzione di pneumatici. I principi fondamentali della Chimica Verde sono stati utilizzati per il disegno chimico delle sintesi riportate nella presente tesi, utilizzando, substrati bio-based per la preparazione di nuovi materiali. Nello specifico, sono stati sintetizzati materiali termoindurenti derivanti da origine naturale, con l'obiettivo di sostituire la resorcina e l'Hexametossimetilmelamina (HMMM), tipici compositi derivanti dal petrolio, durante la preparazione di compositi elastomerici extra-rinforzati. Successivamente, materiali derivanti da fonti lignocellulosiche sono stati utilizzati come substrato di origine naturale per la sintesi di composti pirrolici, con l'intento di sostituire gli agenti di accoppiamento industriali maggiormente utilizzati, anch'essi a base di petrolio. Lo zolfo, un sottoprodotto della raffinazione del petrolio, e i composti pirrolici sono stati poi impiegati come nuovi substrati nella sintesi di copolimeri bio-circolari. La reattività dei poli(zolfo-co-Pirrolo) è stata poi studiata tramite la preparazione di compositi elastomerici, paragonando i risultati sperimentali ottenuti con i risultati tipici di mescole al cui interno è presente il tipico agente reticolante utilizzato industrialmente oggigiorno. Infine, è stata effettuata la modifica chimica della lignina con composti pirrolici utilizzando la tecnica di estrusione reattiva. I nuovi addotti sono stati impiegati per la preparazione di applicazioni per l'adesione gomma-tessile e di composti di gomma extra-rinforzati. Infine, gli addotti Lignina-Pirrolo ottenuti tramite estrusione reattiva sono stati utilizzati anche come riempitivi rinforzanti per la preparazione di materiali termoplastici di alto valore basati su Polibutilene adipato tereftalato (PBAT).
Biosourced materials for elastomer nanocomposites
NADDEO, SIMONE
2023/2024
Abstract
Technology is defined as "the application of scientific knowledge for practical purposes." Beyond this definition, technology embeds concepts such as problem-solving, optimization, and productivity. In all the human history, science and technology have been foundational pillars in the development of prosperous societies. Over the time, technology pushes its limits beyond what was once considered possible, an example is the integration of Generative Artificial Intelligence into everyday tasks. Thus, technology can be seen as a dynamic concept, capable of adapting its-self to global and societal needs. In light of pressing issues such as climate change and environmental challenges, modern society urgently requires a shift towards circular and sustainable practices. Among the various sectors that need an environmental transition, particular attentions have to be focused on scientific fields, due to its significant impact in every-day life. Globally, billions of tons of materials are produced annually. For instance, the global market of elastomer composites is expected to reach 2.7 billion units by 2025. Elastomer composites, particularly those used in tire manufacturing, are integral to various aspects of daily life, facilitating the movement of people and goods. Despite their essential role, these composites are predominantly made up of non-renewable sources, including fillers, coupling agents, vulcanization agents, and thermoset materials, all of which are oil-based and contribute to significant environmental impacts. Consequently, there is an urgent need to develop bio-based alternatives suitable for tire applications. This thesis explores the synthesis, characterization, and application of novel classes of bio-based molecules and materials for use in tire production, according to the basic principles of Green Chemistry and by using, where possible, bio-based building blocks for the preparation of new materials. Specifically, bio-based building blocks were used for the synthesis of thermoset materials, with the objective of replacing oil-derived Resorcinol and Hexamethoxymethylmelamine (HMMM) in the preparation of extra-reinforced composites. Then, lignocellulosic derivatives were used as the bio-based building blocks for synthesizing pyrrole compounds, aiming to replace conventional industrial, oil-based coupling agents. Sulfur, a by-product of petroleum refining, and pyrrole compounds were employed as novel substrates to create bio-circular poly(Sulfur-co-Pyrrole) copolymers, intended as substitutes for traditional oil-based crosslinking agents commonly used in rubber composites. Finally, chemical modification of Lignin with pyrrole compounds was conducted using Reactive Extrusion technique. The novel adducts were used for the preparation of rubber-to-textile adhesion applications and extra-reinforced rubber compounds. All the novel material were tested in the formulation and production of new rubber compounds. Finally, Lignin-Pyrrole adducts obtained by Reactive extrusion were used as reinforcing fillers for the preparation of high valuable thermoplastic materials based on Polybutylene adipate terephthalate (PBAT).| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/228932