[ES] Este trabajo de investigación tiene como objetivo general el desarrollo de formulaciones sostenibles a base de ácido poliláctico (PLA) mediante la incorporación de resinas naturales, resina de colofonia y derivados de resina de colofonia como agentes modificadores. La génesis de la presente tesis doctoral parte del interés de evaluar el efecto de los derivados de colofonia en las propiedades del PLA, tras observar los efectos positivos generados por estos aditivos en polímeros biodegradables de almidón termoplástico (TPS). Al tener como punto de partida los efectos positivos de los derivados de colofonia en el TPS, sería fácil continua la evaluación de los mismos aditivos en el PLA. Sin embargo, como secuencia razonable se comenzó por analizar los efectos de la propia resina de colofonia, y un derivado simple, continuando posteriormente con el análisis de derivados más complejas. Para finalizar con el análisis de derivados de colofonia en las propiedades del PLA, se utilizó un derivado experimental con el doble de complejidad. Este es derivado de colofonia con aducto de anhídrido maleico. A diferencia de la resina de colofonia, los derivados de colofonia presentan mayor estabilidad térmica y mayor estabilidad frente a la oxidación al aire libre. La evaluación de los efectos de la resina de colofonia y sus derivados en las propiedades del PLA se realizaron en cuatro estudios, compilados a su vez en tres grupos. Como epilogo de la investigación, se evaluó la posibilidad de incorporar la resina natural de la flor de Clusia rosea al ácido polilactico. Esta flor es conocida como Copey o mamey silvestre, la cual es una planta endémica del caribe. La evaluación del efecto de esta resina en el PLA se realizó como estudio número cinco, dando lugar a un último grupo, número cuatro. ¿ Grupo 1, uso de resinas de colofonia y un derivado común (ambos de bajo peso molecular). o Primer estudio ¿ Grupo 2, uso de dos derivados de colofonia (de alto peso molecular). o Segundo estudio ¿ Grupo 3, uso de derivado de colofonia con aducto de anhídrido maleico. o Tercer estudio o Cuarto estudio ¿ Grupo 4, evaluación de resina natural de flor de Clusia rosea. o Quinto estudio El procesado de los materiales se realizó por incorporación directa de los derivados de colofonia, mediante extrusión fundido. A continuación, las mezclas extruidas fueron trituradas en forma de granza o pellet, para posteriormente producir probetas normalizadas de ensayo mediante inyección por moldeo, las cuales se utilizaron en la caracterización. / [CA] Aquest treball de recerca té com a objectiu general el desenvolupament de formulacions sostenibles a base d'àcid polilàctic (PLA) mitjançant la incorporació de resines naturals, resina de colofònia i derivats de resina de colofònia com a agents modificadors. La gènesi de la present tesi doctoral part de l'interés d'avaluar l'efecte dels derivats de colofònia en les propietats de l'àcid polilàctic, després d'observar els efectes positius generats per aquestos additius en polímers biodegradables de midó termoplàstic (TPS). En tindre com a punt de partida els efectes positius dels derivats de colofònia en el TPS, seria fàcil continuar l'avaluació dels mateixos additius en el PLA. No obstant això, com a seqüència raonable es va començar per analitzar els efectes de la pròpia resina de colofònia, i un derivat simple, continuant posteriorment amb l'anàlisi de derivats més complexos. Per a finalitzar amb l'anàlisi dels derivats de colofònia en les propietats del PLA, es va utilitzar un derivat experimental amb el doble de complexitat. Aquest és derivat de colofònia amb adducte d'anhídrid maleic. A diferència de la resina de colofònia, els derivats de colofònia presenten major estabilitat tèrmica i major estabilitat enfront de l'oxidació a l'aire lliure. L'avaluació dels efectes de la resina de colofònia i els seus derivats en les propietats del PLA es van realitzar en quatre estudis, compilats al seu torn en tres grups. Com epilogue de la investigació, es va avaluar la possibilitat d'incorporar la resina natural de la flor de Clusia rosea a l'àcid polilàctic. Aquesta flor és coneguda com Copey o mamey silvestre, la qual és una planta endèmica del caribe. L'avaluació de l'efecte d'aquesta resina en el PLA es va realitzar com a estudi número cinc, donant lloc a un últim grup, número quatre. ¿ Grup 1, ús de resines de colofònia i un derivat comú (tots dos de baix pes molecular). o Primer estudi ¿ Grup 2, ús de dos derivats de colofònia (d'alt pes molecular). o Segon estudi ¿ Grup 3, ús de derivat de colofònia amb adducte d'anhídrid maleic. o Tercer estudi o Quart estudi ¿ Grup 4, avaluació de resina natural de flor de Clusia rosea. o Cinqué estudi El processament dels materials es va realitzar per incorporació directa dels derivats de colofònia, mitjançant extrusió. A continuació, les mescles extruides van ser triturades en forma de gransa o pèl·let, per a posteriorment produir provetes normalitzades d'assaig mitjançant injecció per emotlament, les quals es van utilitzar en la caracterització. / [EN] This research aims to develop sustainable formulations based on polylactic acid (PLA) by incorporating natural resin, rosin resin, and rosin resin derivatives as modifying agents. The genesis of this doctoral thesis is based on the interest in evaluating the effect of rosin resin derivatives on the properties of polylactic acid after observing the positive results generated by these additives in biodegradable polymers of thermoplastic starch (TPS). Having as a starting point the positive effects of rosin resin derivatives in TPS, it would be easy to continue evaluating the same additives in PLA. However, as a proper sequence, the evaluations were initiated by analyzing the effects of the rosin resin and a simple derivative, then continuing to investigate more complex derivatives. To finish with the analysis of rosin resin derivatives in the properties of PLA, an experimental rosin resin derivative with twice the complexity was used. This is a rosin resin derivative with maleic anhydride adduct. Unlike rosin resin, rosin resin derivatives exhibit higher thermal and oxidation stability. The effects evaluation of rosin resin and its derivatives in the properties of PLA were carried out in four studies. They were compiled into three groups. As an epilogue to this research, the possibility of incorporating the natural resin of the Clusia rosea flower into polylactic acid was evaluated. This flower is called Copey or wild mamey, an endemic plant native to the Caribbean. This resin effect in the PLA was evaluated as study number five, giving rise to the last group, number four. ¿ Group 1, use of rosin resin and a common derivative (both of low molecular weight). ¿ First study ¿ Group 2, use of two rosin resin esters (high molecular weight). ¿ Second study ¿ Group 3, use of rosin reisn derivative with maleic anhydride adduct. ¿ Their study ¿ Fourth study Group 4, evaluation of the natural resin from the Clusia rosea flower. ¿ Fith study The material was processed by directly incorporating the rosin resin derivatives by melt extrusion. Subsequently, the extruded mixtures were crushed as pellet to produce normalized testing samples through injection molding. These testing samples were then used in the characterization. / Gracias a la Universitat Politècnica de València y al grupo de investigación DEMES por el apoyo a través del contrato predoctoral para la formación de personal investigador financiado por la estructura de investigación de la UPV – subprograma 2 (FPI-2018-S2-31946). Al Programa de Movilidad para estudiantes de doctorado de la Universitat Politècnica de València por la ayuda para “Estancias en Centros Extranjeros de Prestigio”. / Rosa Ramírez, HDL. (2023). Desarrollo de formulaciones de ácido poliláctico (PLA) basadas en la incorporación de derivados de la colofonia [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/194754

Polylactic acid (PLA) is an aliphatic polyester, derived from sustainable natural sources that is biodegradable and can be industrially composted. This material has been in the spotlight recently due to its sustainability and properties. However it has been invented in 1932 by Carothers and then patented by DuPont in 1954 (Standau et al. 2019). The properties of this material though limit its use for applications mainly in the medical sector and in some cases single use packaging. In this research, PLA based blends with improved rheological and thermomechanical properties are investigated. The focus is based in proposing strategies in improving these properties based on commercial methods and processing techniques. In this work, commercial grade PLA has been blended with polycaprolactone (PCL) and polybutylene succinate (PBS) in binary and ternary formulations via twin screw extrusion. PCL has been known to act as an impact modifier for PLA, but to cause a corresponding reduction in strength. Results showed that the binary PLA blends containing PBS and PCL, had reduced viscosity, elastic modulus and strength, but increased strain at break and impact strength. Morphological and thermal analysis showed that the immiscibility of these additives with PLA caused these modifications. Incorporation of a small loading of PBS had a synergistic effect on the PLA-PCL blend properties. Miscibility was improved and enhanced mechanical properties were observed for a ternary blend containing 5wt% of both PBS and PCL compared to binary blends containing 10% of each additive. To increase heat resistance of PLA, the material’s crystallinity has to be increased. However PLA has a relatively slow crystallisation rate making it difficult and expensive to be used in commercial applications where heat resistance is needed. For this reason the chiral nature of PLA has been used to investigate the effect of stereochemistry of PLA in crystallisation. Optically pure PDLA was added to its enantiomer in small amounts (up to 15%) and the properties and crystallisation mechanism of these blends was investigated. Results showed that the addition of PDLA accelerated crystallinity and developed a stucture that increased heat resistance, melt strength and stiffness. Finally, a processing model of developing a fully stereocomplex PLA part based in commercial techniques is proposed. Injection moulded PLA showed even higher heat resistance without the need of further processing the product (increasing crystallinity). / Floreon

La conception de nanoparticules (NPs) polymériques pour le transport de médicaments dans la peau repose sur la compréhension du rôle de leurs compositions chimiques sur leurs interactions avec la peau, notamment la peau pathologique. Ce travail s'est attaché à définir le rôle de la composante hydrophile des NPs sur l'administration cutanée d'un principe actif lipophile modèle (cholécalciférol). Il a été remarqué que la composition hydrophile de polymères amphiphiles à base de PLA conditionnait les propriétés physicochimiques des NPs, notamment la taille, la surface, et la structure, tout comme la protection du cholécalciférol. Concernant l'absorption cutanée sur peau intacte, la composante hydrophile de NPs de 100 nm a eu peu d'influence. Une absorption cutanée du cholécalciférol légèrement plus importante a toutefois été obtenue à partir des NPs très riches en PEG hydrophile en comparaison aux NPs peu PEGylées. A l'inverse sur peau lésée, les NPs hydrophobes et négativement chargées de PLA seul ont permis la meilleure absorption du cholécalciférol. D'une part, la dynamique de la structure des NPs très PEGylées a permis une meilleure mouillabilité de la peau et une possible extraction de lipides cutanés, pouvant faciliter l'absorption sur peau intacte. D'autre part, la composition de la peau a conditionné la structure des NPs, puisque, sur peau lésée, les espèces ioniques libérées de la peau ont déstabilisé les NPs peu ou non PEGylées. Par adhésion à la surface de la peau, les agrégats de PLA ont pu ainsi faciliter l'absorption sur peau lésée.Lors du développement de formulations de NPs, leur composition chimique est donc à optimiser selon l'état pathologique de la peau / The design of clinically efficient polymeric nanoparticles (NPs) for skin drug delivery is based on the understanding of the influence of NPs chemical composition on their interactions with the skin tissue, notably the pathological skin. The aim of this work was to determine the influence of the hydrophilic component of polymeric NPs on the delivery of a lipophilic model drug (cholecalciferol).It was noticed that the polymeric hydrophilic composition of amphiphilic PLA-based NPs conditioned the NPs physico-chemical properties, notably in terms of size, surface properties, structure and drug protection. With regard to absorption into intact skin, the hydrophilic composition of 100 nm NPs had little impact. Only a slightly greater skin absorption was obtained from NPs with high hydrophilic PEG content compared to weakly PEGylated NPs. On the contrary in impaired skin, hydrophobic and negatively charged non-PEGylated NPs (PLA NPs) provided the best drug absorption. On the one hand, the dynamic structure of highly PEGylated NPs providing better skin wettability and potential skin lipids extraction may have contributed for increased absorption in intact skin. On the other hand, skin condition altered the NPs structure since it was observed that a non-negligible quantity of ionic species was released from impaired skin, triggering the destabilization of weakly or non-PEGylated charged NPs. However, only PLA aggregates sedimented/adhered onto the skin surface, which could have facilitated absorption in impaired skin. The polymeric hydrophilic composition of NPs and the pathological skin condition are therefore essential points to consider when designing nanoformulations

No description available.

Les travaux de thèse retranscrits dans ce mémoire ont pour sujet l’élaboration de nouveaux ligands pour la coordination de métaux et l’application des complexes correspondants pour la catalyse et la thérapie.La première partie du manuscrit traite de l’élaboration de ligands phosphine-diène, de leurs analogues saturés et des complexes arène-ruthénium correspondants. Le départ d’arène permet au ligand phosphine-cycloheptadiène de former avec le ruthénium un complexe bimétallique cationique où le ligand est chélate κ-P/diène-η4. Ces complexes ont été appliqués en catalyse pour l’addition radicalaire par transfert d’atome (ATRA) de CCl4 au styrène. Lors de l’utilisation de conditions dures, la supériorité des complexes « diène » a pu être mise en évidence par rapport aux analogues saturés.La seconde partie rapporte le développement de nouveaux analogues de base de Schiff : les « salicylamidines ». L’utilisation de différentes voies de synthèse a permis d’obtenir plusieurs générations de ligands. Ils ont été utilisés pour la coordination de métaux et sont particulièrement adaptés à la formation de complexes avec le zinc et l’aluminium. Certains de ces composés ont été utilisés pour la polymérisation par ouverture de cycle (ROP) de lactides et ont démontré une bonne activité.La dernière partie concerne la synthèse et l’évaluation de complexes métalliques comme agents anticancéreux. Des complexes phosphine-or et phosphine-ruthénium ont été synthétisés et évalués pour leur activité antiproliférative. Les complexes phosphine-or présentent une activité remarquable, meilleure que le cisplatine. La nature de l’arène des complexes phosphine-ruthénium influe fortement sur leur activité, les dérivés « benzoate d’éthyle » donnent des cytotoxicités significativement meilleures que les analogues « p-cymène ». Des complexes de titane et de zirconium avec un ligand de type aza-dipyrrométhène ont été synthétisés. Une étude préliminaire de leurs propriétés photophysiques a été réalisée et a indiqué que les composés étaient fluorescents. L’étude de leur propriété anticancéreuse a démontré une faible cytotoxicité. / The subject of this thesis concerns the development of new ligands, their coordination chemistry, and the synthesis of the corresponding metal complexes for catalysis and therapy.The first part of this work relates to the synthesis of diene-phosphine ligands, their saturated analogs, and the corresponding arene-ruthenium complexes. Arene decoordination allows the formation of a cationic bimetallic complex where the ligand is diène-η4/κ-P coordinated to the ruthenium. These complexes have been applied to atom transfer radical addition (ATRA) of CCl4 to styrene. When harsh reaction conditions are used, the superiority of the “diene” complexes is highlighted comparing to saturated analogs.The second part concerns the development of new Schiff base analogs: the “salicylamidines”. Several ligand generations have been obtained following different synthetic paths. They have been used for metal coordination, and are especially well-suited for the formation of zinc and aluminium complexes. Some of the compounds have been applied to ring opening polymerization (ROP) of lactides, and demonstrated good activity.The last part reports on the synthesis and assessment of metal-based anticancer agents. Some phosphine-gold and phosphine-ruthenium complexes have been synthesized and tested for their antiproliferative activity on several cancer cell lines. The phosphine-gold complexes showed impressive activities, better than cisplatine. Activity of phosphine-ruthenium is strongly influenced by the nature of the arene, ethyl benzoate derivatives are significantly more cytotoxic than p-cymene ones. Titanium and zirconium complexes with aza-dipyrromethene ligand were synthesized. Preliminary photophysical study was performed and indicated fluorescence. Their anticancer properties were assessed, and they are only poorly cytotoxic.

Les plastiques sont aujourd'hui des matériaux ubiquitaires utilisés dans tous les aspects de notre vie quotidienne, en particulier pour l'emballage alimentaire. Cependant, après usage, les plastiques sont une source de pollution de notre environnement naturel. Certains plastiques biodégradables et biosourcés sont déjà disponibles sur le marché, comme l’acide polylactique (PLA), mais ils présentent des performances inférieures. Ce travail de thèse vise à: 1) étudier la stabilité des films de PLA dans diverses conditions de température, d'humidité relative, de pH, d'exposition à des liquides ou à des vapeurs... 2) mieux comprendre l'impact de certains procédés industriels tels que les traitements corona ou pressage à chaud sur le PLA 3) combiner le PLA à des couches de gluten de blé afin de produire des complexes ayant des propriétés barrière plus élevées.Les films de PLA ont été produits par la société Taghleef Industries sur demande et avec des traitements de surface spécifiques, comme le traitement Corona. Des films et des enductions à basede gluten de blé ont été développés à l’échelle laboratoire ainsi que des complexes tricouches PLA- gluten-PLA. Les propriétés physiques et chimiques des films ont été étudiées par différentes techniques issues des sciences des matériaux et des aliments ont été utilisées, telles que l’analyse enthalpique différentielle (DSC), l'analyse thermogravimétrique (TGA), la chromatographie d'exclusion de taille (SEC), la microscopie de force atomique (AFM), la microscopie électronique (SEM), la spectroscopie infrarouge à transformée de Fourier (ATR-FTIR) et la spectroscopie de rayons X (XPS). Les propriétés fonctionnelles telles que la perméabilité à la vapeur d'eau, à l'oxygène (O2), au dioxyde de carbone (CO2) ou à l'hélium (He), la sorption de gaz et de vapeurs, les propriétés mécaniques et de surface ont également été étudiées.Exposés au CO2, les films de PLA présentent une isotherme de sorption linéaire avec l’augmentation de pression. Cependant les modifications physiques et chimiques induites à des pressions élevées n'affectent pas son utilisation dans le domaine d’application alimentaire. Au contraire, lorsque les films de PLA sont exposés à l'humidité à l'état liquide ou vapeur, leur dégradation survient après deux mois à 50 ° C (essai accéléré) suite à son hydrolyse. Cette détérioration chimique, mise en évidence par une diminution significative de la masse molaire, entraine une perte de transparence, mais également par une augmentation de la cristallinité. Par ailleurs, le pH n'affecte pas le taux d'hydrolyse, ce qui est d'un intérêt essentiel pour conditionner des aliments humides.Les films à base gluten de blé ont été choisis pour leurs propriétés de barrière élevées lorsque l’humidité relative reste faible. L'incorporation de lipides n'a pas apporté d'amélioration de leurs performances barrières. Cependant, l'utilisation d’un procédé d’homogénéisation à haute pression a permis une meilleure dispersion du gluten, ce qui a conduit à des films plus homogènes ayant ainsi de meilleures propriétés fonctionnelles. Ces conditions ont donc été retenues pour réaliser des complexes à 3 couches par assemblage d'une couche de gluten de blé entre deux couches de PLA en utilisant un pressage à chaud (10 MPa, 130 ° C, 10 min).La technologie de pressage à chaud montre une forte influence sur les films de PLA, de gluten et sur les tricouches. Elle induit une cristallisation accrue du PLA, ce qui augmente ses propriétés de barrière d'environ 40% et 60%, respectivement pour l'eau et l'oxygène. Cela masque par contre l’effet du traitement corona. D’autre part, le pressage à chaud induit une restructuration du réseau de gluten qui améliore les propriétés de barrière aux gaz des complexes, mais provoque aussi une évaporation de l'eau à l'interface gluten / PLA défavorable à l’adhésion des couches (...) / Poly(lactic acid) (PLA) is a biodegradable and renewable polyester, which is considered as the most promising eco-friendly substitute of conventional plastics. It is mainly used for food packaging applications, but some drawbacks still reduce its applications. On the one hand, its low barrier performance to gases (e.g. O2 and CO2) limits its use for applications requiring low gas transfer, such as modified atmosphere packaging (MAP) or for carbonate beverage packaging. On the other hand, its natural water sensitivity, which contributes to its biodegradation, limits its use for high moisture foods with long shelf life.Other biopolymers such as wheat gluten (WG) can be considered as interesting materials able to increase the PLA performances. WG is much more water sensitive, but it displays better gas barrier properties in dry surroundings. This complementarity in barrier performances drove us to study the development of multilayer complexes PLA-WG-PLA and to open unexplored application scenarios for these biopolymers.This project was thus intended to better understand how food components and use conditions could affect the performances of PLA films, and how these performances could be optimized by additional processing such as surface modifications (e.g. corona treatment and coatings).To that aim, three objectives were targeted:- To study the stability of industrially scale produced PLA films in contact with different molecules (CO2 and water) and in contact with vapour or liquid phases, with different pH, in order to mimic a wide range of food packaging applications.- To better understand the impact of some industrial processes such as corona or hot press treatments on PLA.- To combine PLA with WG layer to produce high barrier and biodegradable complexes.Different approaches coming from food engineering and material engineering were adopted. PLA films were produced at industrial scale by Taghleef Industries with specific surface treatments like corona. Wheat gluten films, coatings and layers were developed and optimized at lab scale as well as the 3-layers PLA-WG-PLA complexes. Different technologies able to mimic industrial processes were considered such as hot press, high pressure homogenization, ultrasounds, wet casting and spin coating. The physical and chemical properties of PLA films were then studied at the bulk and surface levels, from macroscopic to nanometer scale. The functional properties like permeability to gases (e.g. O2 and CO2) and water, gas and vapour sorption, mechanical and surface properties were also investigated.Exposed to CO2, PLA films exhibited a linear sorption behaviour with pressure, but the physical modifications induced by high pressure did not affect its use for food packaging. However, when exposed to moisture in both liquid and vapour state (i.e. environments from 50 to 100 % relative humidity (RH)), PLA was significantly degraded after two months at 50 °C (accelerated test) due to hydrolysis. This chemical deterioration was evidenced by a significant decrease of the molecular weight, which consequently induced a loss of transparency and an increase of the crystallinity. The hydrolysis was accelerated when the chemical potential of water was increased, and it was surprisingly higher for vapour compared to liquid state. In addition, pH did not affect the rate of hydrolysis.Knowing much better the limitation of PLA films, the challenge was to improve its functional properties by combining them with WG, as a high gas barrier bio-sourced and biodegradable polymer. The use of high pressure homogenization produced homogeneous WG coatings, with improved performances. This process was thus selected for making 3 layer complexes by assembly of a wheat gluten layer between two layers of PLA, together with corona treatment and hot press technologies.Corona treatment applied to PLA physically and chemically modified its surface at the nanometer scale (...) / I materiali plastici convenzionali trovano impiego in tutti campi della nostra vita, specialmente nel settore del packaging alimentare, ed in seguito all’utilizzo contaminano e danneggiano il nostro ecosistema. Materiali plastici derivanti da risorse naturali e biodegradabili, come acido polilattico (PLA), sono attualmente disponibili sul mercato anche se caratterizzati da performances inferiori.Questo progetto di dottorato è mirato 1) allo studio della stabilità di film di PLA a varie condizioni di stoccaggio come temperatura, umidità relativa, pH, o esposizione a vapori o gas; 2) a comprendere meglio le influenze di alcuni processi industriali come trattamento corona e hot press nelle proprietà dei film di PLA; 3) a sviluppare complessi multistrato tra film di PLA e di glutine che abbiano proprietà barriera più elevate rispetto ai singoli film.Gli imballaggi a base di PLA sono stati prodotti da Taghleef Industries, produttore leader nel settore e dotato di infrastrutture atte ai trattamenti di modificazione di superfice come il trattamento corona. I film a base di glutine e i coatings sono stati sviluppati e ottimizzati su scala di laboratorio, così come i complessi trilaminari PLA-glutine-PLA.Le proprietà fisiche e chimiche dei film di PLA sono state investigate a livello di superficie, così come a livello di bulk. Diverse tecniche analitiche, provenienti dal campo delle scienze dei materiali e delle scienze degli alimenti, sono state adottate in questo progetto di dottorato come calorimetria differenziale a scansione (DSC), termogravimetria (TGA), cromatografia di esclusione molecolare (SEC), microscopia a forza atomica (AFM), microscopia elettronica a scansione (SEM), spettrofotometria infrarossa a trasformata di Fourier in riflettanza totale attenuata (ATR-FTIR) e spettroscopia fotoelettronica a raggi X (XPS).Le proprietà funzionali come le permeabilità al vapore acqueo (H2O), all’ossigeno (O2), al diossido di carbonio (CO2) o all’elio (He) sono state investigate, cosi come l’assorbimento di gas e/o vapori, le proprietà meccaniche e le proprietà di superfice.Nonostante i film di PLA assorbano linearmente CO2 a pressioni crescenti, l’assorbimento di tale gas è ridotto a basse pressioni in modo da non modificare le sue proprietà fisiche – come contrariamente osservato quando il PLA è esposto a CO2 ad alte pressioni – e da non influenzare negativamente il suo utilizzo come imballaggio alimentare. Ad ogni modo, quando i film di PLA sono esposti ad ambienti umidi, o quando sono immersi in acqua liquida, sono significativamente degradati per idrolisi dopo due mesi di stoccaggio a 50 °C (test accelerato). Questo deterioramento chimico è stato evidenziato da una significativa riduzione del peso molecolare del PLA che, conseguentemente, induce una sua perdita di trasparenza e ne incrementa la sua cristallinità. Inoltre, è stato evidenziato che il pH non influenza la velocità di idrolisi. Quest’informazione ha importanza pratica per possibili utilizzi di PLA come imballaggio di alimenti ad alta umidità.Il glutine è stato scelto per le sue alte proprietà barriera, quando è protetto da ambienti ad alta umidità. Si è visto che l’incorporazione di lipidi non porta con sé grandi miglioramenti nelle performances dei film a base di glutine. Invece, l’utilizzo della tecnologia di omogeneizzazione ad alte pressioni permette una migliore dispersione del glutine, ottenendo film più omogenei e con migliori proprietà funzionali. Questa tecnologia è stata quindi scelta per produrre i complessi multistrato, intercalando i film di glutine tra due film di PLA, usando il trattamento hot press (10 MPa, 130 °C, 10 min). Si è osservato che il trattamento hot press modifica le proprietà dei film di PLA, di glutine e dei film multistrato Hot press induce cristallizzazione in PLA, e conseguentemente aumenta le sue proprietà barriera complessive, approssimativamente al 40 % all’acqua e al 60 % all’ossigeno (...) / Los materiales plásticos tradicionales son utilizados en todos los campos de nuestra vida y en particular modo como embajales de productos alimenticios; los cuales después de ser utilizados contaminan y dañan nuesto medio ambiente. Materiales plásticos derivados de recursos naturales y biodegradables, como el ácido poliláctico (PLA) se encuentran actualmente disponibles en el mercado a pesar de sus menores performances. Este proyecto de doctorado está orientado 1) al estudio de la estabilidad de películas de PLA bajo diferentes condiciones como temperatura, humedad relativa, pH o exposición a vapores o gases, 2) comprender los efectos en las propiedades de las películas de PLA de algunos procesos industriales como el tratamiento corona y hot press, 3) desarrollar complejos multicapas de PLA y gluten que tengan propiedades barrera mejores que las de las películas individuales.Los embalajes a base de PLA han sido producidos por Taghleef Industries, productor líder en el sector y dotado de las infraestructuras industriales adaptadas a los tratamientos superficiales como el tratamiento corona. Las películas de gluten y los coatings han sido desarrollados a escala de laboratorio, así como los complejos tricapa PLA-gluten-PLA.Las propiedades físicas y químicas de las películas de PLA han sido investigadas a nivel de superficie así como a nivel de bulk. Diferentes técnicas de análisis, frecuentemente utilizadas en los campos de las ciencias de los materiales y de las ciencias de los alimentos, han sido empleadas en este proyecto como calorimetría diferencial de barrido (DSC), análisis termogravimétrico (TGA), cromotagrafía de exclusión por tamaño (SEC), microscopía de fuerza atómica (AFM), microscopía electrónica de barrido (SEM), espectroscopía de infrarrojos por transformada de Fourier con reflectancia total atenuada (ATR-FTIR) y espectroscopía fotoelectrónica de rayos X (XPS).Las propiedades funcionales de los embalajes como las permeabilidades al vapor de agua, al oxígeno (O2), al dióxido de carbono (CO2) o al helio (He) han sido investigadas, asi como la absorción de gases/vapores, las propiedades mecánicas y las propiedades superficiales. A pesar de que las películas de PLA absorven linealmente CO2 a presiones mayores, la absorción del gas es reducida a bajas presiones y no modifica las propiedades físicas del PLA, como contrariamente sucede cuando el PLA es expuesto a altas presiones de CO2. Por lo tanto, su influencia en las propiedades funcionales del PLA es mínima en las normales aplicaciones alimentarias. De todos modos cuando los embalajes de PLA son expuestos a ambientes húmedos o cuando son sumergidos en agua, procesos de hidrólisis los degradan significativamente después de dos meses de conservación a 50 °C (test acelerado). Este deterioramiento químico ha sido evidenciado por una significativa reducción del peso molecular del PLA, que en consecuencia induce una pérdida de transparencia y un aumento de su cristalinidad. Además, se ha observado que el pH no influye en la velocidad de hidrólisis. Esta información tiene una importancia práctica para posibles usos del PLA como embalajes de alimentos a alta humedad. El gluten ha sido elegido por sus altas propiedades barrera cuando es protegido de ambientes a alta humedad. La incorporación de lípidos en las películas de gluten no han mejorado sus performances. Pero la tecnología de la homogenización a altas presiones ha permitido mejorar la dispersión del gluten, obteniendo películas más homogéneas y con mejores propiedades funcionales. Esta tecnología ha sido, por lo tanto, elegida para producir los complejos multicapa, intercalando las películas de gluten entre dos de PLA, utilizando el tratamiendo hot press (10 MPa, 130 °C, 10 min) (...)

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With the recent rise of 3D-printing as a form of manufacturing and their advantages for quick prototyping there is an interest for 3D-printed optical components. This thesis tests how well 3D-printed quasi-optical components preform and verify measurements with electromagnetic simulations. Measurements were made using a 60GHz FM-CW radar as well with a trihedral reflector, and tested on 3D-printed PLA lenses printed using an Ultimaker 2+. The measurements made are of the refractive index of the material, as well as the focal length of the lenses. Results showed PLA having a refractive index close to n = 1.654 in the 60GHz region. Results also showed the lenses having consistent properties like focal length and gain, two lenses having focal length of 23.7 and 23.9 mm which are close to the simulation of 24.05 mm. These findings shows 3D printed quasi-optical components have sufficient performance for use of prototyping or production depending on use. There are also some questions that have arisen like how does crystallisation in the plastic affect the components properties? And how does the PLA degrading affect the quality of the lenses over time? / På grund av framgångar inom 3D-utskrivning på senaste tiden som en form av tillverkning och dess fördelar med snabb framtagande av prototyper finns det ett intresse för utskrivna optiska komponenter. Detta examensarbete testar hur väl 3D-utskrivna kvasioptiska komponenter funger\-ar och verifierar testresultat med elektromagnetiska simuleringar. Mät\-ning\-arna gjordes med en FM-CW radar och en trihedral reflektor, och testade PLA linser utskrivna med en Ultimaker 2+. Mätningar\-na gjordes på materialets brytningsindex samt linsernas brännvidd. Resultaten visade att PLA har ett brytningsindex nära n = 1.654 i 60GHz området. Resultaten visade även hur linserna har konsekventa egenskaper som brännvidd och förstärkning. De två slutgiltiga linserna hade en brännvidd på 23.7 and 23.9 mm vilket är nära simuleringen på 24.05 mm. Dessa resultat visar att 3D-utskrivna komponenter har tillräcklig prestanda för användning i framtagande av prototyper eller produktion beroende på användning. Det finns en del frågor som kommit till, som hur påverkar plastens kristallisation komponentens egenskaper? Och hur påverkar PLAs nedbrytande linsernas kvalité?

Made available in DSpace on 2016-12-08T17:19:26Z (GMT). No. of bitstreams: 1 Marindia Decol.pdf: 3575085 bytes, checksum: bed6c0ed662d3c76c64b6cfdac902d8b (MD5) Previous issue date: 2015-07-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Poly (lactic acid) (PLA) is a rigid and brittle thermoplastic polymer, and poly (ε-caprolactone) (PCL) is a thermoplastic polymer of lower rigidity and higher toughness than PLA. Combination of these properties through the blend PLA/PCL has been studied successfully to change the final properties of the PLA. The addition of multiwalled carbon nanotubes (MWCNT) in the blend PLA/PCL may induce peculiar orphologies depending on their location, resulting in the getting new properties or modifying the properties of the PLA matrix. This study aimed to evaluate the effect of adding the PCL, the compatibilizer Cesa-mix and MWCNT the final properties of the PLA. Mixtures were prepared in internal mixer chamber coupled to a torque rheometer and subjected to characterizations of morphological, thermal, mechanical and electrical properties. In the morphological analysis, there was a 37% reduction in the average size of the phases of the PCL blends PLA/PCL with the addition of compatibilizer Cesa®- mix, a heterogeneous distribution of MWCNT the PLA matrix and a selective location of MWCNT in phase PCL. With respect to thermal properties, the addition of the compatibilizing PCL and did not significantly affect the thermal degradation onset temperature (Tonset) of the PLA, but the addition of the MWCNT in PLA resulted in decreased Tonset nanocomposites. The melting temperature did not change significantly with the addition of PCL, the compatibilizer and MWCNT on the PLA matrix. Already cold crystallization temperature decreased and the degree of crystallinity of the PLA increased with the addition of PCL blends and MWCNT in nanocomposites. Decreases of 35% on elastic hardness and 29% in modulus of elasticity was observed with the addition of PCL and compatibilizer Cesa®-mix in the blends PLA/ PCL/AC/2,5%. With the addition of MWCNT was observed an increase of 6,8% on elastic hardness and 8% in the modulus of elasticity of PLA/CNT mixtures with 1,0% w/w. Blends of PLA/PCL with 0,5% and 1,0% w/w CNT with and without compatibilizer, had a decrease in modulus of elasticity and elastic hardness. No significant changes were observed in the electric resistance of the samples with the addition of the compatibilizer, the PCL and MWCNT with 0,5% and 1,0% w/w. Selective location of MWCNT the PCL phase had great influence on morphological, thermal, mechanical and electrical properties of nanocomposites. / O poli(ácido lático) (PLA) é um polímero termoplástico rígido e frágil, e a poli(ε-caprolactona) (PCL) é um polímero termoplástico de menor rigidez e maior tenacidade que o PLA. A combinação destas propriedades através da blenda PLA/PCL tem sido estudada com êxito no auxílio à alteração das propriedades finais do PLA. A adição de nanotubos de carbono de paredes múltiplas (NTCPM) na blenda PLA/PCL pode induzir a morfologias peculiares dependendo da sua localização, resultando na obtenção de novas propriedades ou na alteração das propriedades da matriz PLA. Este trabalho teve como objetivo avaliar o efeito da adição do PCL, do compatibilizante Cesa-mix e dos NTCPM nas propriedades finais do PLA. As misturas foram preparadas em misturador de câmara interna acoplado a reômetro de torque e submetidas à caraterizações das propriedades morfológicas, térmicas, mecânicas e elétricas. Na análise morfológica, observou-se uma redução de 37% no tamanho médio das fases de PCL nas blendas PLA/PCL com a adição do compatibilizante Cesa®- mix, uma distribuição heterogênea dos NTCPM na matriz PLA e uma localização seletiva dos NTCPM na fase PCL. Em relação às propriedades térmicas, a adição do PCL e do compatibilizante não afetaram significativamente na temperatura de início de degradação térmica (Tonset) do PLA, porém a adição de NTCPM no PLA resultou em decréscimo na Tonset dos nanocompósitos. A temperatura de fusão não apresentou variação significativa com a adição do PCL, do compatibilizante e dos NTCPM na matriz PLA. Já a temperatura de cristalização a frio diminuiu e o grau de cristalinidade do PLA aumentou com a adição de PCL nas blendas e dos NTCPM nos nanocompósitos. Diminuições de 35% na dureza elástica e de 29% no módulo de elasticidade foram observadas com a adição do PCL e do compatibilizante Cesa®-mix nas blendas PLA/PCL/AC 2,5%. Com a adição de NTCPM foi observado um aumento de 6,8% na dureza elástica e de 8% no módulo de elasticidade das misturas PLA/NTC com 1,0% m/m. As misturas de PLA/PCL com 0,5% e 1,0% m/m de NTC com e sem compatibilizante, tiveram um decréscimo no módulo de elasticidade e na dureza elástica. Não foram verificadas alterações significativas na resistência elétrica das amostras com a adição do compatibilizante, do PCL e dos NTCPM com 0,5% e 1,0% m/m. A localização seletiva dos NTCPM na fase PCL teve grande influência nas propriedades morfológicas, térmicas, mecânicas e elétricas dos nanocompósitos.

L'utilisation des nanobiotechnologies dans le domaine de la santé est en plein essor. Les nanoparticules de poly(acide lactique) (PLA) représentent un nanosystème biocompatible capable d'accroître la spécificité et l'efficacité de traitements thérapeutiques et vaccinaux administrables par voie muqueuse et intraveineuse. Toutefois, l'optimisation de ces nanosystèmes se heurte à une caractérisation incomplète de leur biodistribution in vivo, en particulier à l'échelle cellulaire.L'objectif de ce travail de thèse est d'enrichir les connaissances sur la biodistribution des nanoparticules de PLA in vivo après administration muqueuse ou intraveineuse, dans le but d'élargir les perspectives d'optimisation et d'utilisation. Animal complexe et adapté pour les études sur organisme-entier, le modèle du poisson-zèbre (Danio rerio) a été utilisé. Pour mener à bien ce projet, une méthodologie rigoureuse d'analyse de la biodistribution des nanoparticules de PLA a été développée. Ce qui permit, après administration par balnéation, d'en révéler le fort tropisme inné envers les cellules dendritiques muqueuses. Ces données ont servi à élaborer une stratégie de ciblage, utilisant la lectine agglutinine de cacahuète, capable d'augmenter la prise en charge des nanoparticules de PLA par les branchies et la peau. Enfin, l'étude du devenir de ces nanoparticules après injection intraveineuse, a révélé de nombreuses interactions avec le système circulatoire. Ce travail a permis d'approfondir la connaissance des interactions des nanoparticules de PLA avec le vivant, soulignant le potentiel prometteur de ces nanoparticules pour la vaccination muqueuse / Medecine shows a growing interest regarding nanobiotechnologies. Among them are poly(lactic acid) (PLA) nanoparticles, which represent a biocompatible and competent nanosystem to heighten the specificity and efficacy of diverse therapeutic and vaccine treatments, following mucosal and intravenous administration. However, the further optimization of such nanosystem is poised by the lack of informations regarding their in vivo biodistribution, especially at the cellular level.The main objective of this PhD is to increment the knowledge about PLA nanoparticles biodistribution in vivo, after muquous and intravenous administration, to further expand their optimisation and use perspectives. The zebrafish model has been utilized to perform this research because of his conserved complexity as well as his suitability for whole-organism studies.To fulfill this project, a precise methodology has been developed to analyze the PLA nanoparticles biodistribution. Which allowed, after bathing administriation, to unveil their robust innate tropism toward mucous dendritic cells. From these data has been established a targeting strategy, utilizing the peanut agglutinin lectin, which has been proved to enhance nanoparticle uptakes by both gills and skin mucosae. Finally, the study of PLA nanoparticles behavior and destiny after intravenous injection, revealed numerous elaborated interactions with the circulatory system.Overall, this work has been able to strengthen our understandings of PLA nanoparticles among living organisms, furthermore highlighting their promizing potential as nanovehicles for mucosal vaccines