The circular economy (CE) has been identified as a catalyst in sustainable development and economic growth that has the potential to move society from the traditional linear model of resource consumption in the form of take-make-waste to an innovative circular model in the form of reduce-reuse-recycle. Transitioning from the linear economy to the CE requires changes in four areas: material and product design, business models, global reverse networks and enabling business environments. This study considers the financing needs of CE companies as a result of business model changes. Through the case studies of Ragn-Sellsföretagen AB and Inrego AB, analysed with secondary data from ING Bank and primary data collected through semi-structured interviews with the case companies, this research sheds more light on the financing needs of circular economy companies and how they are financed. Findings from this research suggest that the financing needs of circular economy companies depend on the value proposition of the company. In accordance with the pecking order of capital structure, all financing needs of the companies studied are financed from internal sources, particularly retained earnings before external debt financing is accessed. Findings indicate the willingness of banks to finance circular economy companies. The results of this research suggest that the circular economy companies studied do not need financial support from the government or its agencies to succeed even though favourable laws are welcomed. They report that their long-term success depends on their ability to remain innovative in their business models, aligning with Schumpeter’s creative destruction model.

The Circular Economy (CE) has quickly become a very popular discourse and is considered to be the solution to the manifold socio-economic challenges of the Anthropocene. What this actually means, however, is still unclear and contested, as different actors and sectors pursue a different degree of ecological, economic, political and social transformation. At the same time, many government organisations have embraced the concept and have set ambitious targets for the CE, with the Dutch government setting a goal of becoming fully circular by 2050. In this context, this paper contributes to the scholarship of CE discourse by critically examining what Dutch policy actors understand by the concept of CE and what this implies for the future of the CE in the Netherlands. This research examines the circular discourse in the Netherlands by means of eleven semi-structured interviews with Dutch policy actors in which the following five narratives are identified: (I) the Equal Collaborations; (II) the Circulate Raw Materials; (III) the Addictive Lifestyle; (IV) the Cross-boundary Cooperation; and (V) the Just Transition. The circular discourse typology of Calisto Friant et al. is put central in this study to analyse the five narratives distinguished. By mapping out the five narratives on this typology grid, this research provides insights into which type of circularity discourse is most strongly advocated among Dutch policy actors. The results of this study show that the Reformist Circular Society discourse is most firmly upheld through the identified narratives, which discourse offers very optimistic perspectives for the circular future of the Netherlands by combining economic and environmental objectives. Yet, this particular discourse does not adequately address all the challenges that the CE faces. By examining the CE discourse in the Netherlands, this research aims to contribute to a comprehensive and inclusive discussion on the concept of CE and reveal what circular futures might exist.

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The circular economy has during the last decade gained traction within academia, politics, and business as it is expected to promote sustainable economic growth and tackle resource scarcity. Further, established firms have to be sustainable to create a future return and be competitive. The circular economy can help firms reduce their environmental impact from business activities and enhance the value of resources. Yet, there is a general lack of understanding of the actions leading towards a circular economy and how the adoption of circular economy principles generates value in a business context. The literature argues that through experimentation of circular novelties, established firms can take the first steps in their transition towards a circular business. This thesis aims to contribute with novel empirical data to the literature field of circular economy, strategic niche management, and business model, where the research questions are framed to address the following purpose: explore how established firms experiment with circular economy and how this experimentation influences the firms’ value proposition and creation. To understand its value chain, the firm must realize its context by adopting a meso-level perspective. Grounded on the empirical setting, the empirical findings and the discussion, an analysis allow us to conclude ten propositions of how circular economy experimentation unfold within firms and how circular economy implementation at the micro-level impact the value chain. The propositions can be divided into three areas of contributions. First, the findings contribute with knowledge on how circular experimentation evolves within the established firm. Second, the thesis contributes with an increased understanding of how the circular economy experimentation within the established firms is affected by the surrounding sectoral actors. Third, the study makes analytical contributions of how circular economy experiments within the established firms influence their value proposition, creation, and capture. / Cirkulär ekonomi har under det senaste decenniet fått en stark attraktion inom den akademiska, politiska och industriella världen, eftersom den förväntas främja hållbar ekonomisk tillväxt och tackla den växande resursbristen. Fortsatt måste företag vara hållbara för att skapa framtida avkastning och för att vara konkurrenskraftiga. Dock finns det generellt en brist på förståelse för de åtgärder som leder till en cirkulär ekonomi samt hur implementeringen av cirkulär ekonomi principer genererar värde i ett affärssammanhang. Litteraturen hävdar att genom experimentering av cirkulära innovationer kan etablerade företag ta de första stegen i sin övergång till en cirkulär verksamhet. Avhandlingen syftar till att bidra med nya insikter till litteraturfältet cirkulär ekonomi, strategic niche management och affärsmodeller, där forskningsfrågorna är utformade för att adressera syftet med denna studie: utforska hur etablerade företag experimenterar med cirkulär ekonomi och hur detta påverkar företagens värde erbjudande och skapande. För att förstå dess värdekedja måste företag förstå sitt sammanhang genom att anta ett perspektiv på mesonivå. Den empiriska utformningen, de empiriska resultaten och diskussionen, tillåter oss att konkludera tio propositioner uppdelade i tre områden om hur experiment med cirkulär ekonomi utvecklas inom företag och hur implementering av cirkulär ekonomi på mikronivå påverkar värdekedjan. Således ger denna avhandling tre huvudsakliga bidrag. Först bidrar resultaten med kunskap om hur cirkulära experiment utvecklas inom det etablerade företaget. För det andra bidrar avhandlingen med en ökad förståelse för hur den cirkulär ekonomins experiment inom de etablerade företagen påverkas av de omgivande sektoriella aktörerna. För det tredje ger studien analytiska bidrag till hur experiment med cirkulär ekonomi inom de etablerade förtegen påverkas deras värde erbjudande, skapande och fångande.

Few have missed out on the fact that the world's carbon dioxide emissions need to be reduced, and the need to switch to a circular economy in order to save earth’s resources is increasingly discussed. In Sweden, the construction sector accounts for more than a third of all generated waste and almost a quarter of all hazardous waste. Therefore, it is necessary to prepare for a transition to a circular economy in the construction industry, where reuse and recycling of materials as well as waste management are highly prioritized issues. As the contractor is a crucial actor in achieving circular economy in the construction sector due to their technical competence and potentially large opportunities to influence the degree of climate impact, the focus of the study was chosen to be from a contractor's perspective. Since a contractor's change to a circular economy also includes an organizational change, it becomes an interesting aspect to take into account as well. Furthermore, the study aims to examine the main motivational factors, opportunities, challenges and financial risks the contractor faces in a transition to a circular economy, both internally in the organization and in a broader perspective in relation to other actors. Thus, it enables an examination of what opportunities there are for the contractor to go from "word to action". The study is conducted according to qualitative principles and the data collection is based on semi-structured interviews where a majority of the respondents represent different parts of the construction sector, with relevant knowledge and competence. The results show that the contractors' motivation to make a transition is partly based on seeing future competitive advantages, but also on a more mandatory nature, as new laws and regulations appear to a greater extent. Possibly, the use of financial incentives in procurement can increase the contractor’s motivation. Identified challenges at an organizational level include difficulties in understanding the concept of circular economy and the management’s role in their communication with employees. Other barriers that have been identified are the lack of a well-functioning and mature market for second-hand materials and the difficulty in assessing the quality of these. The largest identified financial risk for the contractor is mainly related to responsibility for the guarantee of reused materials, as repairing measures can be costly. An important question for the contractor is therefore how risk allocation should be designed. Briefly speaking, it seems that much can be achieved and many of the barriers reduced through close collaboration with other actors in the sector, e.g. clients, architects, suppliers, and consultants. In final, there are some first steps that the contractor can start with in a transition. Although risks can be reduced, they are inevitable in the transition to a circular economy, especially in the beginning. The contractor should therefore, provided that they work with a like-minded client, dare to test circularity in smaller steps. This may, for example, be to gradually introduce reused components into projects or carrying out smaller pilot projects to obtain knowledge. Once knowledge is built up, they should invest in the right marketing, not least to make themselves attractive to suitable clients. It is not optimal for the contractor to passively wait for a client's directive or the establishment of a mature secondary market before they begin their work towards a circular economy. There is always an opportunity to start with what they have at their disposal, for instance, focusing on how to reduce internal waste as much as possible and use their technical competence to come up with circular initiatives in construction projects. / Att det behöver ske en minskning av världens koldioxidutsläpp har undgått ett fåtal, och det talas alltmer om behovet av att ställa om till en cirkulär ekonomi för att spara på jordens resurser. I Sverige står byggsektorn för mer än en tredjedel av allt genererat avfall, och nästan en fjärdedel av allt farligt avfall. Av den anledningen är det nödvändigt att ställa om till en cirkulär ekonomi i byggbranschen, där återbruk av material och avfallshantering är starkt prioriterade frågor. Då byggentreprenören är en avgörande aktör för att uppnå cirkulär ekonomi i byggsektorn, i och med teknisk kompetens och potentiellt stora möjligheter att påverka graden av klimatpåverkan, valdes studiens inriktning till att utgå från byggentreprenörens perspektiv. En byggentreprenörs förändring till cirkulär ekonomi innefattar i grund och botten även en organisationsförändring, och därför är även den aspekten av intresse att ta i beaktning. Vidare syftar studien till att undersöka vilka huvudsakliga motivationsfaktorer, möjligheter, utmaningar och ekonomiska risker byggentreprenören står inför vid en omställning till cirkulär ekonomi, både internt i organisationen och ur ett bredare perspektiv i relation till andra aktörer. Detta för att se vilka möjligheter som finns för byggentreprenören att gå från “ord till handling”. Studien är utförd enligt kvalitativa principer och datainsamlingen baserad på semistrukturerade intervjuer med till största del respondenter från olika delar av byggsektorn med relevant kunskap och kompetens. Resultaten visar att byggentreprenörernas motivation till att ställa om delvis grundar sig på att de kan se framtida konkurrensfördelar på marknaden men också att den ibland är baserad på en mer tvingande karaktär, då nya lagar och regelverk börjar komma i större utsträckning. Möjligen kan användningen av finansiella incitament i upphandling öka byggentreprenörens motivation. Identifierade hinder på en organisationsnivå innefattar oklarheter kring begreppet cirkulär ekonomi samt ledningens roll i kommunikationen till anställda. Andra hinder som har identifierats är avsaknaden av en välfungerande och mogen andrahandsmarknad samt svårigheten i att bedöma kvaliteten för återbrukade material. Den största ekonomiska risken för byggentreprenören grundar sig främst i garantin för återbrukade material då eventuella garantiåtgärder kan bli kostsamma. En angelägen fråga för byggentreprenören är därför hur ansvarsfördelningen avseende risk bör utformas, och incitament kan troligen komma till nytta även här. I stora drag verkar det som att mycket kan uppnås och många av barriärerna överkommas genom ett tätt samarbete med andra aktörer i sektorn, såsom beställare, arkitekter, leverantörer och konsulter. Slutligen kan konstateras att det finns några första steg som byggentreprenören kan börja med i övergången. Även om risker kan minskas, är de oundvikliga i övergången till en cirkulär ekonomi, särskilt i början. Byggentreprenören bör därför, med förutsättning att de jobbar med en likasinnad beställare, våga testa cirkularitet i mindre steg. Det kan exempelvis handla om att gradvis införa återbrukade komponenter i projekt, eller utföra mindre pilotprojekt för att erhålla kunskap. När kunskap har byggts upp bör de satsa på rätt marknadsföring, inte minst för att göra sig attraktiv för en passande beställare. Det är inte optimalt för byggentreprenören att passivt invänta beställarens direktiv eller en mogen andrahandsmarknad innan de påbörjar sitt arbete mot cirkulär ekonomi. Det finns alltid en möjlighet att börja med det dem själva har rådighet över, exempelvis minska de interna avfallsmängderna så mycket som möjligt samt utnyttja sin tekniska kompetens för att ta cirkulära initiativ i projekt.

Aldrig tidigare har det varit så aktuellt som det är idag, år 2021, att arbeta hållbart och spara på jordens resurser. Mängden material som finns i omlopp idag är stor. Ett långsiktigt arbetssätt för hållbarhet och cirkulärt byggande saknas. Byggbranschen står idag för en femtedel av Sveriges utsläpp av växthusgaser. Utsläppen måste minska för att kunna uppnå Sveriges uppsatta klimatmål. För att minska på utsläppen och bidra till ett mer cirkulärt samhälle behöver byggbranschen genomföra konkreta förändringar. En av dessa förändringar är att börja använda återbrukat material. Kunskapen om prisbilden av återbrukat material är idag låg bland de intervjuade i rapporten. En resurseffektivitet krävs för att vända branschen till att bli mer hållbar. Ett sätt att lyckas är att arbeta med de material och komponenter som redan finns och att arbeta cirkulärt, vilket resulterar i att arbeta med återbruk. Återbruk innebär att en komponent återanvänds i så ursprungligt skick som möjligt. I denna rapport har intervjuer med hållbarhetschefer, arkitekter, forskningsinstitut och återbrukscentral genomförts, tillsammans med en litteraturstudie och en utbildning om återbruk. Dessa tre tillvägagångssätt utgör metoden för rapporten. För att lyckas ställa om till cirkulärt byggande kommer det krävas ett övergripande engagemang från alla olika parter som är inblandade i byggprocessen. Ett samspel och samarbete genom hela processen, tillsammans med ökad kunskap är viktiga faktorer för att få arbetet med återbruk att utvecklas. De främsta drivkrafter med att arbeta med återbruk som har identifierats är: Minska klimatpåverkan Ekonomiskt fördelaktigt att handla återbrukat material Unika gestaltningsmöjligheter Möjlighet att sticka ut och marknadsföra sig som företag De främsta hindren som har identifierats är: Okunskap, inrutade vanor Saknad av kvalitet- och garantisystem Brist på lagerhållning och logistik Brist på återbrukat material och komponenter En fördjupad del av rapporten fokuserar på arkitektens perspektiv, och hur arkitekten kan arbeta för att öka återbruk och cirkulärt byggande. Ur arkitektens perspektiv behöver följande genomföras för ett främjat återbruk: Återbruk i åtanke från tidigt skede i byggprocessen Längre medverkan och delaktighet för arkitekten Flexibilitet i gestaltningen Kvalitetssäkring av återbrukade komponenter Med hjälp av resultatet föreslås i denna rapport slutligen åtta åtgärder för att främja återbruk: Kunskap och nya tankesätt måste utvecklas Beställaren behöver ta ansvar och hårdare lagar och regler behövs Generationsskifte och nya arbetsroller ger nytt synsätt Materialleverantörer måste ta ansvar för sina nya och gamla produkter Bygg dyrt och med hög kvalitet Materialbudget bör införas för att få kontroll på mängden jungfruligt material som används Planera och bygg för återbruk från ett tidigt skede Arkitekten behöver medverka längre genom byggprocessen / It has never been more relevant than today, in 2021, to work with sustainability and to save the resources of the earth. The amount of material that is in the industry today is large and a long- term program focusing on sustainability and a circular business is missing. The construction industry is responsible for a large part of Sweden’s emissions of greenhouse gases. The level of emissions needs to decrease to be able to achieve the goal of a lower environmental impact. To reduce the gas emissions and to contribute to a more circular society, changes need to be made by the construction industry. One of these changes is to begin to work with reused materials. The knowledge of the price picture of recycled material is currently low among the interviewed in the report. Recourse efficiency is therefore necessary to make the industry more sustainable. One way to make this happen is to work with the materials and components already existing, a circular way of working is to reuse materials. Reuse of materials is when a component is reused with minimal to no reconstruction. In this thesis interviews with sustainability managers, architects, a research institute and a warehouse for reused materials has been conducted, together with a literary study and a course in reused materials. These three techniques outline the method of this thesis. To succeed with the readjustment to circular construction, it will take an overall commitment from all different parties involved in the construction process. A cooperation through the entire process, together with an increased knowledge are two important factors to get the work with reuse of materials forward. Driving forces for sustainable practices that were discovered are: Reduce the environmental impact Economically favourable to use reused materials Unique opportunities when designing buildings Opportinity to stand out and to show your company as a sustainable business Obstacles that were discovered are that the industry is developing slowly: Not enough knowledge and habits that are set Lack of regulation on a national level Lack of a system to store reused materials while waiting to be used again Lack of the materials itself One part of the thesis is focusing more in depth on the architect’s perspective and how the architect can work to include more reused materials when designing buildings. From the architects perspective these following suggestions were made to increase reuse of materials: Reuse needs to be included in the process from day one The architect needs to have a longer participation in the building process Flexibility when designing The quality of the product that is being reused has to be able to be proven The result of this thesis suggests eight ways to include and increase reused materials: Knowledge and new ways of thinking needs to evolve The customer must take its responsibility and laws regulating reuse needs to be made A shift in age groups in the industry will make ways for new systems Grosists producing the materials must take their responsibility Build expensive and with good quality A budget for construction materials and components should be made Planning for reuse of materials early on in the process The architect must be involved longer in the construction process

[pt] Este estudo fornece uma análise da relação entre as práticas da economia circular (EC) e o desempenho nas pequenas e médias empresas (PME) na Europa, seguindo uma abordagem multinível. O projeto de pesquisa descreve as etapas envolvidas para atingir esse objetivo. A primeira etapa (artigo 1) examina as tendências da pesquisa existente. Verificamos as variáveis utilizadas, o tipo de dados, o método de análise, o tipo de indústria, o porte da empresa, o tamanho da amostra e o tema ao qual o artigo pertence. Os resultados indicam que não existe um consenso claro sobre a melhor forma de medir e operacionalizar as práticas de EC e o desempenho das empresas, no entanto as variáveis identificadas podem ser utilizadas como guia para futuras pesquisas sobre EC e o desempenho das empresas. Na segunda etapa (artigo 2), investigamos como os indicadores de desempenho econômico, social e ambiental do país PME moderam a relação entre as práticas de EC e o desempenho da empresa. Em resumo, os resultados apoiam que o impacto financeiro da adoção da EC é positivo e é afetado pelo nível de desempenho nacional econômico e ambiental. A terceira etapa (artigo 3) tem como objetivo desenvolver e testar o modelo empírico que inclui moderação por nível meso. Examinamos a função dos intermediarios no envolvimento das PME nas atividades de EC bem como a presença de Redes de Simbiose Industrial (ISN) afeta o desempenho das PME. As conclusões afirmam que as ISN s podem impulsionar a adopção da EC e os intermediários podem ajudar as PME a superar os obstáculos da EC. / [en] This study provides an examination of the relationship between circular economy (CE) practices and firm performance in small and medium-sized enterprises (SMEs) in Europe, following a multi-level approach. The research project outlines the stages involved to reach this goal. The first stage (paper 1) examines the trends in the existing research. We verified the variables used, the type of data, the method of analysis, the type of industry, the size of the company, the size of the sample and the topic to which the article belongs. The results indicate that there is no clear consensus on the best way to measure and operationalize CE practices and firm performance, however the variables identified can be used as a guide for future research on CE and firm performance. The second stage (paper 2) we investigate how the economic, social, and environmental performance indicators of the SME country moderates the relationship between CE practices and firm performance. In summary, the results support that the financial impact of adopting CE is positive, and it is affected by the level of national economic and environmental performance. The third stage (paper 3) the aim is develop and test empirical model include moderation by meso-level. We examined the function of intermediaries in involving SMEs in CE activities, and how the presence of Industrial Symbiosis Networks (ISN) affects SMEs performance. The findings affirm that ISNs can boost CE adoption and intermediaries can assist SMEs in surmounting CE obstacles.

The aim of this project is to investigate the influence of AI on CBMs, specifically focusing on the aggregated dimensions of value proposition, value creation and delivery, and value capture. This study employs a qualitative research design inspired by a deductive approach. A systematic literature review was conducted from scientific articles. Interviews with manufacturing companies and AI experts are also utilized to enrich understanding and validate the theoretical model. A thematic analysis was conducted to extract and examine patterns and themes and from that a framework has been developed about how AI influences the circular business values of value proposition, value creation and delivery, and value creation. The key enablers and challenges are outlined, categorized into three main groups: Technological, Organizational, and Environmental factors. The conclusion is that AI enables CBMs in manufacturing by optimizing materials, enhancing predictive maintenance, improving recycling processes, and enabling dynamic pricing models. Key enablers include robust AI infrastructure, organizational support, and regulatory frameworks. Challenges encompass inadequate infrastructure, data issues, and skill shortages. Competitive pressures and regulations drive adoption but also pose hurdles.

In quantum chemistry, scientists aim to solve the time-independent Schrödinger equation by employing a variety of approximation techniques whose accuracy are typically inversely proportional to their computational cost. This problem is amplified when it comes to chiral molecules, whose stereochemical assignments and associated chiroptical properties can be incredibly sensitive to small changes in their three-dimensional structure, requiring highly accurate theoretical methods. On the other hand, due to the polynomial scaling with system size, it is sometimes impractical to apply such methods to chemical compounds of broad scientific interest, especially when a multitude of low-energy conformations have to be accounted for as well. As a result, the assignment of absolute configurations to chiral compounds remains a tedious task. However, the characterization of these compounds is something that many different scientists are significantly invested in. The ultimate goal, then, is twofold: to gain useful insight by utilizing the electronic structure methods at your disposal while simultaneously developing new approximation techniques that can be used to push the boundaries on what is currently capable in computational chemistry. Therefore, we start by applying widely accepted density functional theory methods to predict optical rotations and electronic circular dichroism for naturally occurring antiplasmodial and anticancer drug candidates. We find that by comparing the computational results directly with those obtained through experimental measurement, we can provide reliable absolute config- uraitonal assignments to a variety of chiral compounds with numerous stereogenic centers. We also present the first ever prediction of vibrational circular dichroism with second-order Møller-Plesset perturbation theory. This extension opens the door to systematically improvable correlated wave function methods that can be employed when density functional theory fails or when higher accuracy results are required. / Doctor of Philosophy / Theoretical chemistry aims to draw a line from a molecule's three-dimensional structure to a set of physical observables, allowing for the efficient prediction of such properties. One family of chemical compounds for which this task becomes increasingly difficult is known as chiral molecules. A chiral compound is defined as one that has a non-superimposable mirror image. The concept of chirality is most tangibly seen with a pair of human hands, which demonstrate this same mirror-like behavior. In the same way that a person has left and right hands, a three-dimensonal handedness can be used to characterize many compounds that are essential to life including enzymes, sugars, and proteins. Although procedures have been developed to consistently isolate pure samples of such compounds, the correct identification of each hand poses a much larger task and costs the global pharmaceutical industry tens to hundreds of millions of dollars every year. As such, gaining insight about these incredibly valuable compounds and their associated properties is a never ending goal for many scientists. One such way to gain insight is through the direct comparison of experimental and calculated properties, namely chiroptical properties. These unique properties define how chiral compounds interact with light. While experimental scientists are limited in the degree to which they can probe a molecule's structure, theoretical chemists have the advantage of knowing the exact three-dimensional structure for the compound they are studying. On the other hand, theoretical chemists rely on comparison to experimental results to develop new methods or apply the available techniques to predict molecular properties. This work begins by attempting to match calculated properties to experimentally measured ones in order to confirm the detailed molecular structure of natural product drug candidates. Through multiple such computational studies, it is shown that the current methods are sometimes limited in the knowledge that they can provide. As a result, it is absolutely necessary to continue to improve on the existing methods. We go on to provide a first-of-its-kind implementation that allows for theoretical chemists to compare their results to experiment in a way that was not previously possible.

Tesis por compendio / [ES] La presente tesis doctoral tiene como principal objetivo el desarrollo de materiales poliméricos que sean respetuosos con el medio ambiente y favorezcan modelos de economía circular, centrando las líneas de investigación en el reaprovechamiento de residuos de la industria del mango y en la utilización de ácido poliláctico (PLA) como principal matriz polimérica. Para ello se emplean diferentes técnicas de procesado como el electrospinning, la extrusión, la inyección o la producción de films por disolución. Además, se plantea la utilización de diferentes aditivos como plastificantes y cargas lignocelulósicas de origen renovable para mejorar las propiedades de estos materiales sin comprometer su alto potencial medioambiental. El primer bloque de la tesis centra sus esfuerzos en el reaprovechamiento de diferentes residuos del mango (uno de los cultivos más populares del mundo), como la piel y el kernel, para desarrollar diferentes materiales con un gran contenido natural. Dentro de los estudios realizados en este bloque se incluye la extracción de almidón a partir del kernel de mango para la posterior fabricación de nanofibras por electrospinning, con gran aplicación en el sector médico. Otros estudios realizados proponen la combinación de matrices poliméricas como el biopolipropileno y el PLA, en combinación con harina de piel de mango y harina de hueso de mango, respectivamente, mediante procesos de extrusión, extrusión reactiva (REX) e inyección. En el caso del biopolipropileno se utilizan además agentes compatibilizantes basados en ácido itacónico para aumentar la adhesión entre las partículas lignocelulósicas de la piel del mango con la matriz polimérica, la cual es altamente apolar. Por otro lado, a las formulaciones de PLA y harina de hueso de mango se le añaden plastificantes como la triacetina y la tributirina para aumentar las propiedades dúctiles del PLA. Un cuarto estudio se enfoca en la producción de films de glicerol con harina de hueso de mango, rica en almidón, para observar cómo afecta el tamaño de partícula de la harina sobre las propiedades de los films. Por último, se propone el desarrollo de materiales termoplásticos ricos en almidón utilizando harina de kernel de mango en combinación con diferentes plastificantes como glicerol, sorbitol y urea. Estos materiales ricos en almidón son procesados por extrusión e inyección y son completamente biodegradables y de origen natural. El segundo y último bloque de la tesis está enfocado a la utilización del ácido poliláctico obtenido de fuentes renovables en procesos de extrusión e inyección. Este poliéster es un polímero biodegradable cuya principal desventaja es su gran fragilidad. Por ello, se han empleado diferentes tipos de plastificantes naturales para incrementar las propiedades dúctiles del PLA. En un primer trabajo, se combina el PLA con α-terpinil acetato, un plastificante de origen renovable. Además, se añade piel de mandarina molida como carga natural para evaluar si este plastificante es capaz de aumentar la ductilidad de mezclas de PLA con cargas lignocelulósicas, obtenido resultados muy positivos. Un segundo trabajo plantea la combinación de PLA con dietil-L-tartrato, un plastificante obtenido del ácido tartárico, encontrado en la uva y el tamarindo, obteniendo elongaciones de más de un 300%. Por último, dos estudios más plantean la combinación de PLA con terpenoides, más concretamente ésteres de geranilo y linalilo. En este sentido, uno de los trabajos se centra en variar la proporción de acetato de linalilo y acetato de geranilo en las composiciones, mientras que el otro trabajo evalúa como afecta la longitud de cadena de los ésteres de geranilo a la plastificación del PLA. Todos los plastificantes utilizados en este bloque ofrecieron resultados muy prometedores, con alargamientos a la rotura superiores al 200% en materiales completamente naturales y biodegradables con gran aplicación en el sector alimentario y del envase y embalaje. / [CA] La present tesi doctoral té com a principal objectiu el desenvolupament de materials polimèrics que siguen respectuosos amb el medi ambient i afavorisquen models d'economia circular, centrant les línies d'investigació en el reaprofitament de residus de la indústria del mango i en la utilització d'àcid polilàctic (PLA) com a principal matriu polimèrica. Per a això s'empren diferents tècniques de processament com l'electrospinning, l'extrusió, la injecció o la producció de films per dissolució. A més, es planteja la utilització de diferents additius com a plastificants i càrregues lignocelulòsiques d'origen renovable per a millorar les propietats d'aquests materials sense comprometre el seu alt potencial mediambiental. El primer bloc de la tesi centra els seus esforços en el reaprofitament de diferents residus del mango (un dels cultius més populars del món), com la pell i el kernel, per a desenvolupar diferents materials amb un gran contingut natural. Dins dels estudis realitzats en aquest bloc s'inclou l'extracció de midó a partir del kernel de mango per a la posterior fabricació de nanofibers per electrospinning, amb gran aplicació en el sector mèdic. Altres estudis realitzats proposen la combinació de matrius polimèriques com el biopolipropilè i el PLA, en combinació amb farina de pell de mango i farina d'os de mango, respectivament, mitjançant processos d'extrusió, extrusió reactiva (REX) i injecció. En el cas del biopolipropilè s'utilitzen a més agents compatibilitzants basats en àcid itacònic per a augmentar l'adhesió entre les partícules lignocelulòsiques de la pell del mango amb la matriu polimèrica, la qual és altament apolar. D'altra banda, a les formulacions de PLA i farina d'os de mango se li afigen plastificants com la triacetina i la tributirina per a augmentar les propietats dúctils del PLA. Un quart estudi s'enfoca en la producció de films de glicerol amb farina d'os de mango, rica en midó, per a observar com afecta la grandària de partícula de la farina sobre les propietats dels films. Finalment, es proposa el desenvolupament de materials termoplàstics rics en midó utilitzant farina de kernel de mango en combinació amb diferents plastificants com glicerol, sorbitol i urea. Aquests materials rics en midó són processats per extrusió i injecció i són completament biodegradables i d'origen natural. El segon i últim bloc de la tesi està enfocat a la utilització de l'àcid polilàctic obtingut de fonts renovables en processos d'extrusió i injecció. Aquest polièster és un polímer biodegradable el principal desavantatge del qual és la seua gran fragilitat. Per això, s'han emprat diferents tipus de plastificants naturals per a incrementar les propietats dúctils del PLA. En un primer treball, es combina el PLA amb α-terpinil acetat, un plastificant d'origen renovable. A més, s'afig pell de mandarina molta com a càrrega natural per a avaluar si aquest plastificant és capaç d'augmentar la ductilitat de mescles de PLA amb càrregues lignocelulòsiques, obtenint resultats molt positius. Un segon treball planteja la combinació de PLA amb dietil-L-tartrat, un plastificant obtingut de l'àcid tartàric, trobat en el raïm i el tamarinde, obtenint elongacions de més d'un 300%. Finalment, dos estudis més plantegen la combinació de PLA amb terpenoids, més concretament èsters de geranil i linalil. En aquest sentit, un dels treballs se centra en variar la proporció d'acetat de linalil i acetat de geranil en les composicions, mentre que l'altre treball avalua com afecta la longitud de cadena dels èsters de geranil a la plastificació del PLA. Tots els plastificants utilitzats en aquest bloc van oferir resultats molt prometedors, amb allargaments al trencament superiors al 200% en materials completament naturals i biodegradables amb gran aplicació en el sector alimentari i de l'envàs i embalatge. / [EN] The present doctoral thesis has as its main objective the development of polymeric materials that are environmentally friendly and promote circular economy models, focusing research on the reuse of waste from the mango industry and the use of polylactic acid (PLA) as the main polymer matrix. Various processing techniques such as electrospinning, extrusion, injection, or cast film are employed for this purpose. In addition, the use of different additives such as plasticizers and lignocellulosic fillers of renewable origin is proposed to improve the properties of these materials without compromising their high environmental potential. The first part of the thesis focuses on the reuse of various mango waste products (one of the most popular crops in the world), such as peel and kernel, to develop different materials with a high natural content. Studies in this section include the extraction of starch from mango kernels for the subsequent production of nanofibers by electrospinning, which have significant applications in the medical sector. Other studies propose the combination of polymeric matrices such as biopolypropylene and PLA, in combination with mango peel flour and mango kernel flour, respectively, through extrusion, reactive extrusion (REX), and injection processes. In the case of biopolypropylene, compatibilizing agents based on itaconic acid are also used to increase the adhesion between lignocellulosic particles from mango peel and the highly apolar polymer matrix. On the other hand, PLA formulations with mango kernel flour are supplemented with plasticizers such as triacetin and tributyrin to enhance the ductile properties of PLA. A fourth study focuses on the production of glycerol films with mango kernel flour, rich in starch, to observe how the particle size of the flour affects the film properties. Finally, the development of starch-rich thermoplastic materials is proposed using mango kernel flour in combination with different plasticizers such as glycerol, sorbitol, and urea. These starch-rich materials are processed by extrusion and injection and are completely biodegradable and of natural origin. The second and final part of the thesis is focused on the use of polylactic acid obtained from renewable sources in extrusion and injection processes. This biodegradable polyester has the main disadvantage of being very brittle. Therefore, different types of natural plasticizers have been used to increase the ductile properties of PLA. In the first study, PLA is combined with α-terpinyl acetate, a renewable plasticizer. In addition, ground tangerine peel is added as a natural filler to evaluate if this plasticizer can increase the ductility of PLA blends with lignocellulosic fillers, yielding very positive results. A second study proposes the combination of PLA with diethyl-L-tartrate, a plasticizer obtained from tartaric acid, found in grapes and tamarind, resulting in elongations of more than 300%. Finally, two more studies propose the combination of PLA with terpenoids, specifically geranyl and linalyl esters. In this regard, one of the works focuses on varying the proportion of linalyl acetate and geranyl acetate in the compositions, while the other study evaluates how the chain length of geranyl esters affects PLA plasticization. All the plasticizers used in this section offered very promising results, with elongations at break exceeding 200% in completely natural and biodegradable materials with significant applications in the food and packaging sectors. / This research is a part of the grant PID2020-116496RB-C22, funded by MCIN/AEI/10.13039/501100011033 and the grant TED2021-131762A-I00, funded by MCIN/AEI/10.13039/501100011033 and by the European Union “NextGenerationEU”/PRTR. Authors also thank Generalitat Valenciana-GVA for funding this research through the grant numbers AICO/2021/025 and CIGE/2021/094. Funded with Aid for First Research Projects (PAID-06-22), Vice-rectorate for Research of the Universitat Politècnica de València (UPV). J. I.-M. wants to thank FPU19/01759 grant funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. J. G.-C. wants to thank FPU20/01732 grant funded by MCIN/AEI/10.13039/ 501100011033 and by ESF Investing in your future. / Gómez Caturla, J. (2024). Desarrollo y caracterización de polímeros de alto rendimiento medioambiental derivados de residuos agroindustriales y aditivos de origen renovable [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/203217 / Compendio