Made available in DSpace on 2016-12-08T17:19:27Z (GMT). No. of bitstreams: 1 Samara Bohn.pdf: 2670870 bytes, checksum: 4b9de8d71921764eee1942da211fad27 (MD5) Previous issue date: 2015-09-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The poly (vinyl chloride) (PVC) is one of thermoplastic polymers most consumed worldwide, because it has a broad scope and can be used from rigid pipes and profiles up toys and extremely flexible films obtained with the addition of plasticizers. The addition of nanofillers in polymer matrices has aroused the interest of many researchers seeking to improve properties of materiais and reduce the cost of producing them. In this work, the objective was to evaluate the effect of plasticizer in the nanoclays dispersion in the polymer matrix of poly (vinyl chloride) (PVC). Three different plasticizers ware used, one being the family of phthalate (dioctyl phthalate DOP), on the family of adipate (dioctyl adipate DOA) and the third, called by some green plasticizers poly (e-caprolactone) PCL. Furthermore, it was also evaluated the effect of clay pre-dispersion in the plasticizer in the properties of the nanocomposites. The samples were prepared in single screw extruder and characterized by means of scanning electron field effect (SEM FEG) and transmission electron microscopy (TEM), diffraction X-ray (XRD), differential scanning calorimetry (DSC) tensile and swelling test. The morphology shows a heterogeneous distribution in the matrix, since phase separation, ocorred and clay agglomerates. However it was found that the use of the pre-dispersion can reduce the agglomerates and form small regions interleaving and further reduce the size of the phases, and found that even if different plasticizers would provide different results. By DRX it was found that the inclusion of clay pre-dispersed by sonication on the matrix promotes increased crytallinity of 75% compared with the sample without DOP clay, other samples had smaller increases. In differential scanning calorimetry it was observed over a Tg heterogeneity in the plasticization of PVC. In tensile teste it was found that inclusion of clay plasticized PVC promoted 5% and 10% in Young s modulus for PVC/DOP samples with sonification and PVC/PCL respectively with magnetic stirring. While the samples decreased with DOA Young s modulus within 19%, and the samples were also had smaller reduction in the migration of the plasticizer during the swelling test. According to the results found was that the clay pre-dispersion in theplasticizer may facilitate intercalation of the some but dosen t eliminate large amounts of agglomerates in the nanocomposity which can have great influence on the properties mechanical, thermal and migration, and the type of palsticizer has a remarkable effect on the nanocomposite. / O poli (cloreto de vinila) (PVC) é um dos polímeros termoplásticos mais consumidos mundialmente, pois o mesmo tem um vasto campo de aplicação podendo ser utilizado desde tubos e perfis rígidos até brinquedos e filmes extremamente flexíveis obtidos com a adição de plastificantes. A adição de nanocargas em matrizes poliméricas tem despertado interesse de muitos pesquisadores, que buscam melhorar propriedades dos materiais e reduzir o custo de produção dos mesmos. Neste trabalho, o objetivo foi avaliar o efeito do plastificante na dispersão de nanoargilas em matriz polimérica de poli (cloreto de vinila) (PVC). Foram utilizados três diferentes plastificantes, sendo um deles da família dos ftalatos (dioctil ftalato - DOP), um da família dos adipatos (dioctil adipato - DOA) e o terceiro, chamado por alguns de plastificante verde poli (ε-caprolactona) PCL. Além disso, também foi avaliado o efeito da pré-dispersão da argila nos plastificantes nas propriedades dos nanocompósitos. As amostras foram preparadas em extrusora monorosca e caracterizadas por meio de microscopia eletrônica de varredura de efeito de campo (MEV-FEG) e microscopia eletrônica de transmissão (MET), difração de raios-X (DRX), calorimetria exploratória diferencial (DSC), ensaios de tração e ensaio de intumescimento. A morfologia apresentou uma distribuição heterogênea na matriz, pois ocorreu separação de fase e aglomerados de argila. No entanto, verificou-se que a utilização da pré dispersão pode reduzir os aglomerados e formar pequenas regiões de intercalação, e ainda reduzir o tamanho das fases, e ainda constatou-se que diferentes plastificantes promovem resultados diferentes. Por meio de DRX constatou-se que a inserção de argila pré-dispersa por sonicação na matriz promove aumento de 75% na cristalinidade em relação a amostra com DOP sem argila, as demais amostras tiveram aumento menores. Na calorimetria exploratória diferencial foi observado mais de uma Tg indicando heterogeneidade na plastificação do PVC. Nos ensaios de tração foi verificado que a inserção de argila no PVC plastificado promoveu aumentos de 5% e 10% no módulo de Young para as amostras PVC/DOP com sonicação e PVC/PCL com agitação magnética, respectivamente. Enquanto que as amostras com DOA apresentaram redução do módulo de Young em até 19%, e também foram as amostras que tiveram a menor redução na migração do plastificante durante os ensaios de intumescimento. De acordo com os resultados foi verificado que a pré-dispersão da argila no plastificante pode facilitar a intercalação da mesma, mas não elimina a grande quantidade de aglomerados nos nanocompósitos o que pode ter grande influência sobre as propriedades mecânicas, térmicas e de migração, bem como o tipo de plastificante influencia de forma considerável sobre os nanocompósitos.

Resumo: Os objetivos deste estudo foram avaliar: 1. o efeito de tratamentos póspolimerização (MW-irradiação por energia de microondas e WB-imersão em água aquecida) sobre o grau de conversão (DC) de resinas acrílicas para reembasamento imediato (Ufi Gel hard-U, Kooliner-K e Tokuso Rebase Fast-T) e de uma resina acrílica para base de prótese (Lucitone 550-L), submetida a dois ciclos de polimerização (LS-curto e LL-longo) por espectroscopia FT-Raman; 2. o peso molecular (M w) do pré-polímero dos materiais U, K, T e L e das amostras polimerizadas da resina K (controle; MW e WB) por GPC; 3. o efeito de MW e WB na temperatura de transição vítrea (Tg) das resinas para reembasamento imediato (Duraliner II-D, K, New Truliner-N, U e T) e da resina para base de prótese (LS e LL) por DSC; 4. o efeito de WB na liberação de compostos residuais (isobutil metacrilato-IBMA, 1,6-hexanediol dimetacrilato-1,6-HDMA e DBNP-dibutil-n-ftalato) a partir das resinas para reembasamento imediato K, N, U e T para saliva artificial por CLAE; 5. o efeito de WB na liberação de produtos de degradação (ácido metacrílico-MA e ácido benzóico-BA) a partir das resinas para reembasamento imediato K, N, U e T para saliva artificial por CLAE. Amostras do grupo controle não foram submetidas a nenhum tratamento. Os resultados de DC (%) foram analisados pelo teste de Kruskal-Wallis ( =0,05). Os resultados de Tg (ºC) foram analisados pela análise de variância (ANOVA), seguido pelo teste de Tukey ( =0,05). Os resultados da liberação de monômero ' 224 residual e plastificante (μg/mL) foram submetidos aos testes de Wilcoxon ou de Mann-Whitney ( =0,05). Os resultados da liberação de produtos de degradação (μg/mL) foram submetidos aos testes de Wilcoxon, Mann-Whitney ou Kruskal- Wallis ( =0,05). Para as amostras do grupo controle, não houve diferenças significantes entre o DC das resinas U e LL e entre...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aims of this study were to evaluate: 1. the effect of post-polymerization treatments (MW-microwave irradiation and WB-water-bath) on the degree of conversion (DC) of reline resins (Ufi Gel hard-U, Kooliner-K, and Tokuso Rebase Fast-T) and denture base resin (Lucitone 550-L), submitted to two polymerization cycles (LS-short and LL-long) by FT-Raman spectroscopy; 2. the molecular weight (M w) of the powder of U, K, T, and L materials and of K polymerized specimens (control; MW; and WB) by GPC; 3. the effect of MW and WB on the glass transition temperature (Tg) of the reline resins (Duraliner II-D, K, New Truliner-N, U and T) and the heat-polymerized resin (LS and LL) by DSC; 4. the effect of WB on the leaching of residual compounds (isobutyl methacrylate- IBMA, 1,6-hexanediol dimethacrylate-1,6-HDMA, and DBNP-dibutyl-nphthalate) from the reline resins (K, N, U, and T) in artificial saliva by HPLC; 5. the effect of WB on the leaching of degradation products (methacrylic acid-MA and benzoic acid-BA) from the reline resins K, N, U, and T in artificial saliva by HPLC. Control group specimens were left untreated. DC (%) data were analyzed using Kruskal-Wallis test (_=.05). Tg (ºC) data were analyzed using ANOVA/Tukey's test (_=.05). The results (æg/mL) of residual monomer and plasticizer leachability were submitted to Wilcoxon or Mann-Whitney tests (_=.05). The results (æg/mL) of degradation products leachability were submitted to Wilcoxon, Mann-Whitney or Kruskal-Wallis tests (_=.05). For DC control specimens, there were no significant differences between U and LL and among LL, K, and T. LS specimens had the highest DC. Only material K exhibited an increased DC after WB. All powders had M w from 4.0x105 to 6.5x105 and narrow M w distributions (2.1 to 3.6). Polymerization and post-polymerization produced K specimens with M w values similar to that of K powder...(Complete abstract, click electronic address below). / Orientador: Ana Lucia Machado / Coorientador: Quezia Bezerra Cass / Banca: Carlos Eduardo Vergani / Banca: Carlos Alberto dos Santos Cruz / Banca: Marcelo Ferraz Mesquita / Banca: Regina Vincenzi Oliveira / Doutor

Nowadays, efforts are being made to reduce the environmental impact on the planet even at soils management. Excavated soils are treated as waste and often end up in landfill or depot landfills. It is an effort to exploit these soils. By adding suitable stabilizing additives, features such as yield fluidity, moisture or compressive strength can be adjusted. This composite can be further liquefactioned by using water and suitable liquefiers or plasticizers. Such iquefactioned soils are a suitable self-compacting grouts dressing for excavation for the laying of utility grids, where it is necessary to fill the hole again. The advantage are low economic demands and the absence of excess waste. In the course of this thesis the situation of soil usability in the Czech Republic will be evaluated and possible technologies of soil adjusters will be described. Further, the known types of stabilizing additives and their influence on soil stabilization will be evaluated and verified. Then, different types of liquefying additives will be evaluated and verified. The aim of the thesis is to develop a new technology of liquefaction and soil stabilization.

Táto práca sa zaoberá zvlákňovaním biopolymérov z taveniny. V teoretickej časti sú zhrnuté doterajšie poznatky o zvlákňovaní poly(3-hydroxy butyrátu) (PHB) a poly(mliečnej kyseliny) (PLA). Následne boli zvláknené polymérne zmesi na báze PHB s rôznym zložením, čo umožnilo štúdium vplyvu PLA, zmäkčovadiel a ich množstva na vlastnosti pripravených vlákien. Boli použité tri komerčné zmäkčovadlá (ATBC, PEG, A6) a dva experimentálne syntetizované. Zvláknenie bolo prevedené na troch rôznych zvlákňovacích linkách. Konvenčné zvlákňovacie linky s odťahovými rýchlosťami nad 150 m/min sa preukázali ako nevhodné pre spracovanie našich zmesí. Kvôli nedostatočnej pevnosti taveniny sú potrebné nízke odťahové rýchlosti. Boli pripravené vlákna s dĺžiacim pomerom 6,4; ktoré boli následne analyzované pomocou GPC, MDSC a ťahovej skúšky. Na základe nameraných teplôt skelného prechodu zmäkčovadlá ATBC a PEG vykázali lepšiu schopnosť zmäkčiť skúmané PLA/PHB zmesi. Vlákna obsahujúce A6 vykazovali najvyššiu pevnosť v ťahu (250 MPa) a modul pružnosti (2,7 GPa). Nakoniec bol skúmaný vplyv starnutia, tepla a vriacej vody na mechanické vlastnosti týchto vlákien.

Di-(2-ethylhexyl)-phthalate (DEHP), an ubiquitous environmental contaminant, has been shown to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies, but the underlying mechanisms are still unknown. We therefore tested the hypothesis that chronic DEHP exposure causes impaired insulin sensitivity, affects body weight, adipose tissue (AT) function and circulating metabolic parameters of obesity resistant 129S6 mice in vivo. An obesity-resistant mouse model was chosen to reduce a potential obesity bias of DEHP effects on metabolic parameters and AT function. The metabolic effects of 10-weeks exposure to DEHP were tested by insulin tolerance tests and quantitative assessment of 183 metabolites in mice. Furthermore, 3T3-L1 cells were cultured with DEHP for two days, differentiated into mature adipocytes in which the effects on insulin stimulated glucose and palmitate uptake, lipid content as well as on mRNA/protein expression of key adipocyte genes were investigated.We observed in female mice that DEHP treatment causes enhanced weight gain, fat mass, impaired insulin tolerance, changes in circulating adiponectin and adipose tissue Pparg, adiponectin and estrogen expression. Serum metabolomics indicated a general increase in phospholipid and carnitine concentrations. In vitro, DEHP treatment increases the proliferation rate and alters glucose uptake in adipocytes. Taken together, DEHP has significant effects on adipose tissue (AT) function and alters specific serum metabolites. Although, DEHP treatment led to significantly impaired insulin tolerance, it did not affect glucose tolerance, HOMA-IR, fasting glucose, insulin or triglyceride serum concentrations. This may suggest that DEHP treatment does not cause impaired glucose metabolism at the whole body level.

E PVC est l'un des polymères les plus employés dans les matériaux actuels et l'adjonction de plastifiants permet de modifier ses propriétés (température de transition vitreuse, module…) permettant ainsi l'utilisation de ce polymères dans des applications où de la souplesse est requise (textiles enduits, par exemple). Actuellement, les phtalates sont les plastifiants les plus utilisés même s'ils sont de plus en plus décriés du fait de leur toxicité. Le développement de nouveaux agents plastifiants est un domaine de recherches intenses et les matières premières bio-sourcées s'avèrent être une alternative intéressante aux plastifiants pétro-sourcés. Le travail de cette thèse se propose d'investiguer le développement de plastifiants du PVC bio-sourcés de type lipidique possédant de surcroit des propriétés ignifugeantes évitant ainsi l'ajout d'additifs supplémentaires dans les formulations de PVC devant résister au feu. Dans un premier temps, l'oléate, le linoléate de méthyle et le diacide (D18 : 1) ont été fonctionnalisés par modification chimique de leurs groupements ester et/ou de leurs insaturations pour mener à des dérivés lipidiques phosphorés. Cinq candidats plastifiants bio-sourcés ont ainsi pu être synthétisés et le scale up de la synthèse de l'un des candidats à l'échelle du kilogramme a pu être réalisé dans le cadre de cette thèse. Dans un deuxième temps, des tests de plastification du PVC avec divers candidats ont été réalisés en collaboration avec la société Serge FERRARI. L'étude des propriétés thermiques, mécaniques et thermomécaniques des films de PVC plastifiés obtenus, comparativement au plastifiant phtalate DINP et au plastifiant bio-sourcé commercial RADIA 7295, a permis d'éliminer différents candidats pour n'en finalement retenir que deux. Des profils de dégradation thermique satisfaisants, des basses valeurs de Tg, des allongements à la rupture importants (320 et 365 % respectivement) et proches de ceux obtenus avec le DINP, ont confirmé l'efficacité plastifiante de ces deux composés phosphorés bio-sourcés. Les tests au feu LOI et au cône calorimètre ont également prouvé le caractère ignifugeant de ces deux composés qui conduisent à des résultats du même ordre de grandeur que ceux atteints avec le plastifiant phosphonate commercial de référence S141 / Poly(vinyl chloride) is one of the most manufactured and consumed thermoplastics in the world. The addition of plasticizers allows modifying its properties (glass transition temperature, modulus…) and then to use this polymer for applications where flexibility is needed (coated textiles, for instance). Nowadays, phthalates are the main candidates for PVC even if they have been more and more controversed due to their possible toxicity. To substitute these petro-based plasticizers, researches are focused on alternative plasticizers based on bio-based raw materials. This PhD work proposes to investigate the development of new bio-based plasticizers for PVC, from lipidic derivatives, and having simultaneously flame retardant properties, avoiding the addition of any other additives in PVC during compounding. In the first part, methyl oleate, methyl linoleate and diacid D18 : 1 have been functionalized by modification of their ester groups and/or their doubles bonds to give phosphorylated lipidic derivatives. Thus, five bio-based plasticizers have been synthesized and the synthesis of one candidate on the scale of the kilogram has been successfully performed during this PhD work. Secondly, the plasticizing efficiency of several candidates with PVC has been evaluated in collaboration an industrial company. Thermal, mechanical and thermomechanical properties of the obtained soft PVC films were studied, in comparison with those obtained with the phthalate plasticizer DINP and the commercial bio-based plasticizer RADIA 7295. These analyses allowed the disposal of some of the bio-based plasticizers to finally keep only two candidates. Satisfying thermal degradation profiles, low Tg, and important elongation at break values (320 % and 365 % respectively) close to those obtained with DINP, confirmed the plasticizing efficiency of these two bio-based phosphorylated plasticizers. Fire tests like the LOI test and the cone calorimeter also proved the flame retardant properties of these two candidates, leading to similar results than the ones reached with the phosphonate plasticizer S141

Tesis por compendio / [ES] El objetivo de esta tesis doctoral radica en el estudio y desarrollo de materiales basados en ácido poliláctico (PLA), con la finalidad de mejorar sus propiedades para su aplicabilidad en diversos sectores industriales. Este estudio se enfoca en la modificación de la fragilidad y rigidez inherentes al PLA mediante la incorporación de diferentes materiales, como plastificantes derivados de aceites vegetales epoxidado y maleinizado del aceite de linaza denominado MLO. Además, se investiga la creación de mezclas binarias con polímeros de mayor ductilidad, como el policarbonato (PC) y el estireno-b-(etileno-ran-butileno)-b-estireno (SEBS), se explora la inclusión de oligómeros de ácido láctico (OLA) y monoterpenos como estrategias para mejorar las propiedades del PLA. Estas investigaciones buscan proporcionar soluciones avanzadas y sostenibles para diversas aplicaciones industriales que demandan materiales con características mejoradas. En el contexto actual de la industria de los polímeros, la búsqueda de materiales sostenibles y respetuosos con el medio ambiente ha adquirido un protagonismo destacado. Esta creciente conciencia ambiental ha impulsado una profunda investigación y desarrollo de soluciones innovadoras que cumplan con los estándares de sostenibilidad y, al mismo tiempo, ofrezcan propiedades y rendimientos excepcionales. Dentro de este marco, la presente investigación se sumerge en el estudio y evaluación de alternativas prometedoras con las que mejorar la fragilidad y rigidez inherentes al PLA mediante la incorporación de diferentes materiales, como plastificantes, oligómeros, compatibilizantes u otros polímeros en mezclas binarias. El primer ámbito de estudio de esta investigación se centra en la incorporación de MLO como un agente compatibilizador en mezclas compuestas por PLA y SEBS. Los resultados de este estudio arrojan evidencia sólida de que el MLO supera de manera significativa a los tradicionales compatibilizadores derivados del petróleo. Se logra un incremento notable en la resistencia al impacto de estas mezclas, lo que es esencial en aplicaciones de envasado que requieren una protección adecuada de los productos contenidos. Además, se destaca que la adición de MLO conlleva una ligera disminución de la temperatura de transición vítrea (Tg) en la fase rica en PLA. Este efecto puede ser beneficioso en términos de flexibilidad, lo que resulta especialmente relevante en el envasado de productos que necesitan adaptabilidad y resistencia a condiciones variables. El segundo plano de investigación se enfoca en la comparación exhaustiva entre compatibilizadores de origen natural y aquellos de procedencia petroquímica en mezclas de PLA y PC. Este análisis confirma que los compatibilizadores naturales, incluyendo MLO y el aceite de linaza epoxidado (ELO), presentan ventajas notables en términos de resistencia al impacto sin comprometer la estabilidad térmica. Este hallazgo subraya la viabilidad y sostenibilidad de los compatibilizadores biobasados en aplicaciones específicas del envasado. Además, se aborda en el concepto de extrusión reactiva (REX) como una estrategia efectiva para potenciar la tenacidad de las mezclas de PLA. Tanto la inclusión de OLA y MLO durante el proceso de REX producen resultados altamente prometedores. Esto incluye un notable aumento en la resistencia al impacto, un atributo crítico en aplicaciones de envasado donde la integridad del producto es esencial. Es importante destacar que la adición de MLO, en particular, resulta en una transparencia sobresaliente, un factor que potencia aún más su idoneidad para aplicaciones de envasado de alimentos. Por último, se profundiza en el estudio de los monoterpenoides no esterificados y su impacto en el PLA. Estos compuestos, entre los que se destacan la carvona, el citral, el citronelal y el eucaliptol, han demostrado ser capaces de mejorar significativamente la ductilidad del PLA sin afectar de manera sustancial su transparencia. Este hallazgo adquiere / [CA] L'objectiu d'aquesta tesi doctoral radica en l'estudi i desenvolupament de materials basats en àcid polilàctic (PLA), amb la finalitat de millorar les seues propietats per a la seua aplicabilitat en diversos sectors industrials. Aquest estudi s'enfoca en la modificació de la fragilitat i rigidesa inherents al PLA mitjançant la incorporació de diferents materials, com a plastificants derivats d'olis vegetals epoxidats i maleinizats de l'oli de llinosa denominat MLO. A més, s'investiga la creació de mescles binàries amb polímers de major ductilitat, com el policarbonat (PC) i el estiré-b-(etilé-ran-butilé)-b-estiré (SEBS), s'explora la inclusió de oligomers d'àcid làctic (OLA) i monoterpens com a estratègies per a millorar les propietats del PLA. Aquestes investigacions busquen proporcionar solucions avançades i sostenibles per a diverses aplicacions industrials que demanden materials amb característiques millorades. En el context actual de la indústria dels polímers, la cerca de materials sostenibles i respectuosos amb el medi ambient ha adquirit un protagonisme destacat. Aquesta creixent consciència ambiental ha impulsat una profunda recerca i desenvolupament de solucions innovadores que complisquen amb els estàndards de sostenibilitat i, al mateix temps, oferisquen propietats i rendiment excepcionals. Dins d'aquest marc, la present investigació se submergeix en l'estudi i avaluació d'alternatives prometedores amb les quals millorar la fragilitat i rigidesa inherents al PLA mitjançant la incorporació de diferents materials, com a plastificants, oligómers, compatibilitzants o altres polímers en mescles binàries. El primer àmbit d'estudi d'aquesta investigació se centra en la incorporació de MLO com un agent compatibilitzador en mescles compostes per àcid poliláctic (PLA) i poliestiré-b-(etilé-ran-*butilé)-b-estiré (*SEBS). Els resultats d'aquest estudi llancen evidència sòlida que MLO supera de manera significativa als tradicionals compatibilitzadors derivats del petroli. S'aconsegueix un increment notable en la resistència a l'impacte d'aquestes mescles, la qual cosa és essencial en aplicacions d'envasament que requereixen una protecció adequada dels productes continguts. A més, es destaca que l'addició del MLO comporta una lleugera disminució de la temperatura de transició vítria (Tg) en la fase rica en PLA. Aquest efecte pot ser beneficiós en termes de flexibilitat, la qual cosa resulta especialment rellevant en l'envasament de productes que necessiten adaptabilitat i resistència a condicions variables. El segon pla d'investigació s'enfoca en la comparació exhaustiva entre compatibilitzadors d'origen natural i aquells de procedència petroquímica en mescles de PLA i policarbonat (PC). Aquesta anàlisi confirma que els compatibilizadors naturals, incloent el MLO i l'oli de llinosa epoxidat (ELO), presenten avantatges notables en termes de resistència a l'impacte sense comprometre l'estabilitat tèrmica. Aquesta troballa subratlla la viabilitat i sostenibilitat dels compatibilizadors de base biològica en aplicacions específiques de l'envasament. A més, s'aprofundeix en el concepte d'extrusió reactiva com una estratègia efectiva per a potenciar la tenacitat de les mescles de PLA. Tant la inclusió de oligómers d'àcid làctic (OLA) com l'aplicació de peròxid de dicumil (DCP) i MLO durant el procés d'extrusió reactiva produeixen resultats altament prometedors. Això inclou un notable augment en la resistència a l'impacte, un atribut crític en aplicacions d'envasament on la integritat del producte és essencial. És important destacar que l'addició de MLO, en particular, resulta en una transparència excel·lent, un factor que potencia encara més la seua idoneïtat per a aplicacions d'envasament d'aliments. Finalment, s'aprofundeix en l'estudi dels monoterpenoides no esterificats i el seu impacte en la PLA. Aquests compostos, entre els quals es destaquen la carvona, el citral, el citronelal i el eucaliptol, han demostrat ser capaços de millo / [EN] The objective of this doctoral thesis is the study and development of materials based on polylactic acid (PLA), with the aim of improving its properties for its applicability in various industrial sectors. This study focuses on the modification of the inherent brittleness and stiffness of PLA by incorporating different materials, such as plasticizers derived from epoxidized vegetable oils and maleinized linseed oil called MLO. In addition, the creation of binary blends with higher ductility polymers such as polycarbonate (PC) and polystyrene-b-(ethylene-ran-butylene)-b-styrene (SEBS) is investigated, the inclusion of lactic acid oligomers (OLA) and monoterpenes are explored as strategies to improve the properties of PLA. This research aims to provide advanced and sustainable solutions for various industrial applications that demand materials with improved characteristics. In the current context of the polymer industry, the search for sustainable and environmentally friendly materials has taken on an outstanding role. This growing environmental awareness has prompted in-depth research and development in the search for innovative solutions that meet sustainability standards and, at the same time, offer exceptional properties and performance. Within this framework, the present research is immersed in the study and evaluation of promising alternatives to improve the inherent brittleness and stiffness of PLA by incorporating different materials, such as plasticizers, oligomers, compatibilizers or other polymers in binary blends. The first area of study of this research focuses on the incorporation of MLO as a compatibilizing agent in blends composed of polylactic acid (PLA) and styrene-b-(ethylene-ran-butylene)-b-styrene (SEBS). The results of this study provide strong evidence that MLO significantly outperforms traditional petroleum-derived compatibilizers. A noticeable increase in the impact resistance of these blends is achieved, which is essential in packaging applications that require adequate protection of the contained products. Furthermore, it is noted that the addition of MLO leads to a slight decrease in the glass transition temperature (Tg) in the PLA-rich phase. This effect can be beneficial in terms of flexibility, which is particularly relevant in packaging products that need adaptability and resistance to variable conditions. The second research plane focuses on the comprehensive comparison between compatibilizers of natural origin and those of petrochemical origin in PLA and polycarbonate (PC) blends. This analysis confirms that natural compatibilizers, including MLO and epoxidized linseed oil (ELO), present notable advantages in terms of impact resistance without compromising thermal stability. This finding underlines the viability and sustainability of biobased compatibilizers in specific packaging applications. Furthermore, the concept of reactive extrusion as an effective strategy to enhance the toughness of PLA blends is further explored. Both the inclusion of lactic acid oligomers (OLA) and the application of dicumyl peroxide (DCP) and MLO during the reactive extrusion process produce highly promising results. This includes a marked increase in impact resistance, a critical attribute in packaging applications where product integrity is essential. Importantly, the addition of MLO, in particular, results in outstanding transparency, a factor that further enhances its suitability for food packaging applications. Finally, the study of non-ester monoterpenoids and their impact on PLA is further explored. These compounds, including carvone, citral, citronellal and eucalyptol, have been shown to significantly improve the ductility of PLA without substantially affecting its transparency. This finding is particularly relevant in the context of packaging applications, where flexibility and resistance to deformation are critical aspects. Thus, these non-ester monoterpenoids present themselves as a promising option for th / Me gustaría realizar especial mención a los proyectos concedidos al grupo de investigación en el que he realizado la tesis doctoral. Por un lado, los proyectos del Ministerio de ciencia e innovación MAT2017–84909–C2–2–R y PID2020–116496RB–C22. Igualmente agradecer a la Generalitat Valenciana por los proyectos AICO/2021/025 y CIGE/2021/094 / Tejada Oliveros, R. (2023). Optimización de las propiedades de tenacidad e impacto de formulaciones de ácido poliláctico (PLA), mediante mezclas con polímeros flexibles y optimización de los sistemas de compatibilización [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/201561 / Compendio

Modern indoor environments contain a vast array of contaminating sources. Emissions from these sources produce contaminant concentrations that are substantially higher indoors than outside. Because we spend most of our time indoors, exposure to indoor pollutants may be orders-of-magnitude greater than that experienced outdoors. Phthalate esters have been recognized as major indoor pollutants. They are mainly used as plasticizers to enhance the flexibility of polyvinylchloride (PVC) products, as well as in humectants, emollients, and antifoaming agents. Phthalates are found in a wide range of consumer products including floor and wall coverings, car interior trim, floor tiles, gloves, footwear, insulation on wiring, and artificial leather. Because these phthalate additives are not chemically bound to the polymer matrix, slow emission from the products to the surrounding air or other media usually occurs. Biomonitoring data suggest that over 75% of the U.S. population is exposed to phthalates. The ubiquitous exposure to phthalates is of concern because toxicological investigations have demonstrated considerable adverse health effects of phthalates and their metabolites. Studies have shown that exposure to phthalates results in profound and irreversible changes in the development of the reproductive tract, especially in males, raising the possibility that phthalate exposures could be the leading cause of reproductive disorders in humans. In addition, effects such as increases in prenatal mortality, reduced growth and birth weight, skeletal, visceral, and external malformations are possibly associated with phthalate exposure. Epidemiologic studies in children also show associations between phthalate exposure in the home and the risk of asthma and allergies. Given the ubiquitous nature of phthalates in the environment and the potential for adverse human health impacts, there is a critical need to understand indoor emissions of phthalates and to identify the most important sources and pathways of exposure. In this study, a model that integrates the fundamental mechanisms governing emissions of semi-volatile organic compounds (SVOCs) from polymeric materials and their subsequent interaction with indoor surfaces and airborne particles was developed. The emissions model is consistent with analogous mechanistic models that predict emission of volatile organic compounds (VOCs) from building materials. Reasonable agreement between model predictions and gas-phase di-2-ethylhexyl phthalate (DEHP) concentrations was achieved for data collected in a previously published experimental study that measured emissions of DEHP from vinyl flooring in two very different chambers. The analysis showed that while emissions of highly volatile VOCs are subject to “internal“ control (through the material-phase diffusion coefficient), emissions of the very low volatility SVOCs are subject to “external“– control (through partitioning into the gas phase, the convective mass transfer coefficient, and adsorption onto interior surfaces). Because of the difficulties associated with sampling and analysis of SVOCs, only a few chamber studies quantifying their emissions from building materials and consumer products are available. To more rigorously validate the SVOCs emission model and more completely understand the mechanisms governing the release of phthalate from polymeric building materials, the emission of DEHP from vinyl flooring was studied for up to 140 days in a specially-designed stainless steel chamber. In the duplicate chamber study, the gas-phase concentration in the chamber increased slowly and reached a steady state level of 0.9 µg/m3 after 30 days. By increasing the area of vinyl flooring and decreasing that of the stainless steel surface in the chamber, the time to reach steady state was significantly reduced, compared to the previous study (1 month vs. 5 months). The adsorption isotherm of DEHP on the interior stainless steel chamber surface was explicitly measured using two different methods (solvent extraction and thermal desorption). Strong adsorption of DEHP onto the stainless steel surface was observed and found to follow a simple linear relationship. In addition, parameters measured in the experiments were then applied in the fundamental SVOCs emission model. Good agreement was obtained between the predictions of the model and the gas-phase DEHP chamber concentrations, without resorting to fitting of model parameters. These chamber studies have shown that the tendency of SVOCs to adsorb strongly to interior surfaces has a very strong influence on the emission rate. Compared to the experimental chamber systems, however, the real indoor environment has many other types of surface that will adsorb phthalates to different extents. The emission rate measured in a test chamber may therefore be quite different to the emission rate from the same material in the indoor environment. For this reason, both a two-room model and a more representative three-compartment model were developed successively to estimate the emission rate of DEHP from vinyl flooring, the evolving gas-phase and adsorbed surface concentrations, and human exposures (via inhalation, dermal absorption and oral ingestion of dust) in a realistic indoor environment. Adsorption isotherms for phthalates and plasticizers on interior surfaces, such as carpet, wood, dust and human skin, were derived from previous field and laboratory studies. A subsequent sensitivity analysis revealed that the vinyl flooring source characteristics, as well as mass-transfer coefficients and ventilation rates, are important variables influencing the steady-state DEHP concentration and resulting exposures. A simple uncertainty analysis suggested that residential exposure to DEHP originating from vinyl flooring may fall somewhere between about 5 µg/kg/d and 180 µg/kg/d. The roughly 40-fold range in exposure reveals the inherent difficulty in using biomonitoring results to identify specific sources of exposure in the general population. This research represents the first attempt to explicitly elucidate the fundamental mechanisms governing the release of phthalates from polymeric building materials as well as their subsequent interaction with interior surfaces. The mechanistic models developed can most likely be extended to predict concentration and exposure arising from other sources of phthalates, other sources of other semi-volatile organic compounds (such as biocides and flame retardants), as well as emissions into other environmental media (food, water, saliva, and even blood). The results will be of value to architects, governments, manufacturers, and engineers who wish to specify low-emitting green materials for healthy buildings. It will permit health professionals to identify and control health risks associated with many of the SVOCs used in indoor materials and consumer products in a relatively inexpensive way. / Ph. D.

Large and ever-increasing numbers of chemicals, including large quantities of a broad spectrum of organic compounds are used in modern society. More than 30 000 of the more than 100 000 chemical substances registered in the EU are estimated to be daily used, of which many will be discharged into the waste-streams handled by municipal sewage treatment plants (STPs). The main objective of the work underlying this thesis was to improve understanding of the relationships between the characteristics of sewage contaminants and their sewage treatment efficiency. Further objectives were to examine the relationships between socio-economic uses of chemicals and sludge quality, and the effects of regulatory actions on sludge quality. The quality of the sewage sludge and the levels and distribution patterns of the sludge contaminants, both within and between the STPs, seem to remain quite constant over time. The overall findings indicate that the levels of contaminants in sewage sludge seem to be largely independent of the location, size and treatment techniques applied at the STPs, and generally, of the types of human activity connected to them. The total and relative concentrations of the sludge contaminants were found to be fairly constant on a dry weight basis, with some exceptions, indicating that the pollutants originate from broad usage and diffuse dispersion rather than (industrial) point sources. The proportion of cyclic methylsiloxanes recovered in sludge seems to strongly depend on their vapour pressure, which decreases with the number of siloxane units. The higher water solubility and biodegradability of organophosphorus flame retardants and plasticizers than polybrominated diphenyl ethers (PBDEs) were also reflected in lower percentages (relative to their national use) found in sludge. Significant time-trends in levels of a-third of the sludge contaminants included in the annual national measurement program were detected over a period of seven years. The levels of compounds displaying significant time-trends generally decreased following declines in the quantities used nationally. However, a quarter of these compounds showed increasing trends, of which the linear methylsiloxanes followed the same trend as used quantities. The decaBDE was also found to be increasing in sludge, probably as a result of the phase-out of pentaBDE and octaBDE. The results indicate that the STP removal efficiency of anthropogenic substances, in Sweden, is generally good and that STPs, at least those in cold climates, do not efficiently remove certain polar contaminants. A non-targeted screening (by use of environmetrics and GCxGC-TOFMS) was performed and found to fulfil the objective to assess the STP removal efficiency, with emphasis to systematically analyse which compound classes that are not efficiently removed using the current STP technology. Many polar aromatic compounds were identified to be poorly removed. The acquired data on levels, profiles and variations in sludge contaminants (sludge quality) extend both the available information and understanding of the degree and nature of sludge contamination, which should help attempts to track changes in its contaminants and revisions, if necessary, of guideline values. This thesis also contributes to improve the knowledge base for the development of future STP technologies, and that archived sewage sludge can be used in retrospective analysis of new and emerging pollutants.

In the last decade, there has been a growing interest in the use of differential sensing for molecular recognition. Inspired by the mammalian olfactory system, differential sensing employs an array of non-selective receptors, which through cross-reactive interactions, create a distinct pattern for each analyte tested. The unique fingerprints obtained for each analyte with differential sensing are studied with statistical analysis techniques, such as principal component analysis and linear discriminant analysis. It was postulated that serum albumin proteins would be applicable to differential sensing schemes due to significant differences in sequence identity between different serum albumin species, and due to the wide range of hydrophobic molecules which are known to bind to these proteins. Consequently, cross-reactive serum albumin arrays were developed, utilizing hydrophobic fluorescent indicators to detect hydrophobic molecules. As such, serum albumin cross-reactive arrays were employed to discriminate subtly different hydrophobic analytes, and mixtures of these analytes, in the form of terpenes and perfumes, plasticizers and plastic explosive mixtures, and glycerides and adipocyte extracts. In this doctoral work, a detailed review of the field of differential sensing, and a thorough study of principal component analysis and linear discriminant analysis in various differential sensing scenarios, are given. These introductory chapters aid in better understanding the methods and techniques applied in later experimental chapters. In chapter 3, serum albumins, a PRODAN indicator, and an additive are shown to discriminate five terpene analytes and terpene doped perfumes. Chapter 4 describes an array with serum albumins, two dansyl fluorophores, and an additive which successfully differentiate the plasticizers found within the plastic explosives C4 and Semtex and simulated C4 and Semtex mixtures. Discrimination of these simulated mixtures was also achieved with this array in the presence of soil contaminants, demonstrating the potential real-world applicability of this sensing ensemble. Finally, chapter 5 details an array consisting of serum albumins, several fluorescent indicators, and a Grubb's olefin metathesis reaction, to differentiate saturated and unsaturated triglycerides, diglycerides, and monoglycerides. Mixtures of glycerides in adipocyte extracts taken from rats with different health states were then successfully discriminated, showing promise for clinical applications in differentiating adipoctyes from pre-diabetic, type 2 diabetic, and non-diabetic individuals. / text