Made available in DSpace on 2014-10-09T12:35:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:03:39Z (GMT). No. of bitstreams: 0 / Pesquisas e publicações sobre polímeros luminescentes vêm sendo desenvolvidas nos últimos anos devido à inovação acadêmica, porém ainda no âmbito nacional possuem aplicação industrial limitada. Marcadores ópticos processados são pouco explorados devido à dificuldade de processamento dos materiais poliméricos luminescentes com estabilidade de luminescência. Os materiais utilizados para o processamento de polipropileno luminescente foram Poliamida 6 (PA6) dopada com complexo sintetizado de [Eu(tta)3(H2O)2] obtida através do processo de diluição do polímero e técnica de derramamento. As poliolefinas, por serem inertes, não se adequam ao procedimento comum de dopagem, assim no presente trabalho, o polipropileno luminescente foi preparado indiretamente por dopagem com poliamida dopada com complexo de európio em processamento por extrusão. As técnicas de caracterização utilizadas foram a Análise Térmica (TG), Calorimetria Exploratória Diferencial (DSC), Difração de Raios-X (XRD), Espectroscopia de infravermelho (FT-IR) e estudo das propriedades fotoluminescentes. A blenda PP/PA6:Eu(tta)3 processada apresentou propriedades luminescentes observadas nas transições intraconfiguracionais de bandas finas 4f6 - 4f6 relativas aos níveis de excitação de energia 7F0 → 5L6 (394nm), 7F0 → 5D3 (415nm), 7F0 → 5D2 (464nm), 7F0 → 5D1 (525nm) e 7F0 → 5D0 (578nm). Tanto a blenda de PP/PA6:Eu(tta)3 e os filmes de PA6:Eu(tta)3 quando expostos a luz UV (365nm) apresentaram luminescência vermelha. Os resultados de TG mostraram que sob atmosfera de O2 o PP dopado PA6:Eu(tta)3 apresentou maior estabilidade do que o PP puro. Neste trabalho foi possível processar PP/PA6:Eu(tta)3 com propriedades térmicas e fotoestabilidade, que permitem sua utilização com marcador óptico em processamentos. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Résumé confidentiel / Résumé confidentiel

The research goal of this work was dedicated to improvement of the properties and enhancement of the application potential of commodity polymer based on polyolefins by choosing different synthesis routes to create new structures and materials. More precisely, the presented study explores different aspects of metallocene and post-metallocene catalyzed olefin polymerization leading to synthesis of novel copolymers and nanocomposites. The first part of this thesis deals with controlled polymerization of α-olefins catalyzed by post-metallocenes. Bis(phenoxyamine) zirconium complexes with [ONNO]-type ligands bearing cumyl (bPA-c) and 1-adamantyl (bPA-a) ortho-substituents were applied. For the polymerization catalyzed by bPA catalyst quasi-living kinetic character is proposed. The bPA catalyst was applied for synthesis of block copolymers by employing the strategy of sequential monomer addition. The blocky structure of the copolymer was successfully achieved and confirmed by NMR techniques. Moreover, the monomodal distribution of molar mass in SEC chromatogram confirmed the absence of homopolymers. In the second part of the work new defined comb-like copolymers (CLC) having a poly(10-undecene-1-ol) (PUol) backbone and densely grafted poly(ε-caprolactone) (PCL) side chains are presented. These copolymers were synthesized in two steps by means of metallocene polymerization followed by ring opening polymerization. Copolymers with varied and adjustable graft length (PCL segments) were synthesized. It was proved that the melting and crystallization temperatures of the CLC correlate with the PCL side chain length, i.e. longer chains result in higher Tm and Tc,o values. The melting enthalpy was found to be asymptotically dependent on the length of PCL side chains. The bulk morphology of the comb-like copolymers is proposed to be lamellar as judged from the TEM micrographs. The third part of the thesis is focused on the synthesis of polypropylene nanocomposites via in situ polymerization. Thereby, organomodified aluminumphosphate with kanemite-type layered structure (AlPO-kan) has been used as novel filler. Melt compounding composites were prepared for comparison purposes to evaluate the influence of in situ synthesis on the dispersion quality of the filler in polymer matrix. Melt compounding of neat AlPO-kan with PP did not lead to formation of nanocomposites. TEM images show macro-composites with the lamellar solid remaining agglomerated. On the contrary, in situ polymerization of propene yielded materials with exfoliated nanocomposite morphology. In XRD, diffractions of the AlPO-kan pilling of layers are not detectable. It can be concluded that the primary existing layers are delaminated. Very fine distribution of the filler in the polypropylene matrix has been impressively demonstrated by TEM.

L’objectif de ces travaux était l’utilisation d’oligomères de polyéthylène fonctionnels comme agents d’interface pour la formulation de matériaux polymères. Une première partie s’est portée sur la compréhension de l’évolution de la morphologie de mélanges composés d’une résine polypropylène ou polyéthylène et d’un oligomère de polyéthylène de faible masse molaire au cours de leur mise en œuvre et de leur cristallisation. Il a été constaté qu’un tel oligomère pouvait être incorporé sans difficulté aux résines sélectionnées, et ce grâce à une diffusion rapide ainsi qu’à une bonne miscibilité à l’état fondu. Cependant, il est apparu que ces mélanges étaient sujets à une séparation de phase solide-liquide lors de leur cristallisation, entraînant la formation de matériaux biphasiques à l’état solide. Dans une deuxième partie, un système réactif composé de deux oligomères fonctionnels a été étudié comme une potentielle stratégie de compatibilisation de mélanges polyéthylène/polyamide. Malgré les morphologies et propriétés intéressantes observées, il a été conclu que l’utilisation d’un tel système réactif n’était pas efficace comparé aux agents compatibilisants usuels. Enfin, des oligomères de polyéthylène fonctionnels ont été étudiés en tant qu’agents d’interface dans du polyéthylène renforcé par des fibres de verre dans l’optique d’en améliorer la facilité de mise en œuvre et les propriétés mécaniques. Il a ainsi été démontré que des oligomères avec les fonctionnalités appropriées pouvaient être utilisés comme agents d’interface en réduisant les interactions interparticulaires au cours de la mise en œuvre et en améliorant l’adhésion interfacial matrice-fibre à l’état solide / The objective of this work was to use end-functionalized polyethylene oligomers as interface agents in glass fibre-reinforced thermoplastics as well as compatibilizer precursors in immiscible polymer blends. The first part of this work was focused on the understanding of the morphology developments occurring during the melt processing and crystallization of binary systems where a low molar mass polyethylene oligomer was blended with polypropylene and polyethylene resins. It was found that the polyethylene oligomer was easily incorporated into the selected polyolefins thanks to rapid molecular diffusion and good miscibility in the molten state. However, it appeared that the blends underwent solid-liquid phase separation upon crystallization, leading to biphasic materials in the solid state. In a second part, a reactive system consisting of two functional oligomers was studied as a new strategy for the compatibilization of immiscible polyethylene/polyamide blends. Despite the interesting morphologies and properties observed, it was concluded that the use of such a reactive system did not result in efficient compatibilization compared to commonly used compatibilizer precursors. Lastly, polyethylene oligomers with various functionalities were investigated as interface agents in glass fibre-reinforced polyethylene, with the aim of improving both processability and mechanical properties. It was demonstrated that polyethylene oligomers with adequate functional groups could be successfully used as dispersants by reducing interparticle interactions during melt processing as well as coupling agents improving matrix-filler interfacial adhesion in the solid state

This Master´s thesis deals with heterogeneous photochlorination of polyolefins and especially with the photochlorination of polypropylene itself. In the theoretical part the available information about properties, manufactory and application of chlorinated polyolefins, specifically polyethylene and polypropylene, is provided. The basic principles of the photochemistry are described, which are further applied to the issue of photochemistry chain reactions and photochemical halogenations, mainly photochlorinations. The practical part includes design and realization of few types of equipment for the heterogeneous photochlorination of polypropylene done at low temperatures (to 50° C) by gaseous chlorine in bulk or chlorine suspended in suspension of PP in CCl4. Series of chlorination was accomplished, which was varied in the type of PP, in the way of dosage Cl2 and in the period of high pressure mercury lamp irradiation (1–90 minutes). The chlorine content in prepared samples was determined by the gravimetry with ATR-FTIR spectroscopy, as well as by the Shöniger combustion method. Their accuracies were than compared. The chlorine content dependence on the period of chlorination and on the porosity of initial PP was established.

Utomhusprodukter gjorda i plast är sårbara för nedbrytning på grund av UV-energi från solljus. För att stoppa denna fotonedbrytning används UV-stabilisatorer i plastmaterial; en av huvudkategorierna är hindrade aminljusstabilisatorer (HALS, hindered amine light stabilizers). Detta projekt ämnade att utveckla analytiska metoder passande för polymera HALS-föreningar som används i polyolefin-produkter. Huvudfokuset låg på vätskekromatografi med antingen UV eller masspektrometri (MS) detektion. Identifiering lyckades till viss del, extraktion misslyckades, och det gjordes inga kvantifieringsförsök. Detta examensarbete utfördes som ett samarbete mellan KTH och företaget Norner AS. På grund av detta har detaljerna såsom vilka HALS som användes, hur sammansättningen av elueringsgradienter förändrades och masspektrum från MS analys tagits bort eller ändrats till generiska termer. Högpresterande vätskekromatografi (HPLC, high-performance liquid chromatography) med metoden normalfas (normal phase) ansågs vara ett otillfredsställande alternativ på grund av begränsningen av lämpliga lösningsmedel. Både för HPLC och LC-MS-analys användes omvänd fas (reverse phase) med en C18 50 mm kolonn. Gällande HPLC-analys visade sig en våglängd på 240 nm för UV-detektion vara lämplig. För MS-detektion användes positiv elektrosprayjonisering på grund av föreningarnas basiska pKa-värden. Elueringsgradienten med de mest tillfredsställande resultaten var gradientversion 5, med vatten som lösningsmedel A och metanol som lösningsmedel B. En variant av denna gradient användes för LC-MS; gradientversion 5 mod följer samma mönster men med vatten + Y vol% syra som lösningsmedel A, för att möjliggöra jonisering. Additiv UV 2 har låg löslighet i polära lösningsmedel, men genom förtvålning kunde additiv UV 2 lösas i metanol. Med gradientversion 5 mod har förtvålad additiv UV 2 en retentionstid på 1,2 minuter i både HPLC och LC-MS-analys. För HPLC-analys av additiv UV 3 användes gradientversion 5 som resulterade med en retentionstid på 16,8 minuter, och för LC-MS med gradientversion 5 mod 16 minuter. Analys av additiv UV 5 med HPLC gav en retentionstid på 2 minuter med gradientversion 5, och för LC-MS-analys med gradientversion 5 mod var retentionstiden 1,3 minuter. På grund av inkonsekventa resultat mellan HPLC-analyser eller mellan HPLC och LC-MS-resultat kunde inte retentionstid för identifiering av additiven UV 1, UV 4 och UV 6 bestämmas. Extraktion av polymerprover med olika HALS gjordes i toluen vid 80 °C under en timme. I HPLC var det ingen skillnad i kromatogrammen mellan de olika HALS-produkterna. Resultaten från LC-MS stödde resultaten från HPLC, så slutsatsen att extraktionsmetoden inte var framgångsrik drogs. En anledning till detta kan vara att detektionsgränsen i MS och UV överstiger den extraherade halten av HALS. / Outdoor plastic products are vulnerable to degradation due to UV energy from sunlight. To hinder this photodegradation UV stabilizers are used in plastic materials; one of the main categories is hindered amine light stabilizers (HALS). This project aimed to develop analytical methods suitable for polymeric HALS used in polyolefin products. Liquid chromatography was the primary analytical method, with either UV or mass spectrometry (MS) detection. Identification of HALS was partially successful, the attempted extraction was unsuccessful, and there was no attempt at quantification. This thesis was performed as a collaboration between KTH and the company Norner AS. Due to this, the details such as which HALS were used, how the composition of elution gradients changed, and the mass spectrum from MS analysis have been removed or changed to generic terms. The high-performance liquid chromatography (HPLC) method normal phase was deemed as an unsatisfactory option due to the limitation of appropriate solvents. For HPLC and LC-MS analysis reversed phase with a C18 50 mm column was used. In HPLC analysis, a wavelength of 240 nm for UV detection was found to be suitable. For MS detection, positive electrospray ionization was used due to the compounds' basic pKa values. The elution gradient with the most satisfactory results was gradient version 5, with water as solvent A and methanol as solvent B. A variant of this gradient was used for LC-MS; gradient version 5 mod follows the same pattern but with water + Y vol% acid as solvent A, to enable ionization. UV 2 has low solubility in polar solvents, but through saponification UV 2 could be dissolved in methanol. With gradient version 5 mod, saponified UV 2 has a retention time of 1.2 minutes in both HPLC and LC-MS analysis. For HPLC analysis of additive UV 3, gradient version 5 was used which resulted in a retention time of 16.8 minutes, and for LC-MS with gradient version 5 mod 16 minutes. Analysis of UV 5 with HPLC gave a retention time of 2 minutes with gradient version 5, and for LC-MS analysis with gradient version 5 mod the retention time was 1.3 minutes. Due to inconsistency in results between HPLC analysis or between HPLC and LC-MS results, retention time for identification of additives UV 1, UV 4, and UV 6 could not be stated.  Extraction of polymer samples with different HALS was done in toluene at 80 ॰C for one hour. In HPLC, there was no difference in the chromatograms between the different HALS compounds. The results from LC-MS supported the results from HPLC, thus it was concluded that the extraction method was not successful. A reason for this could be that the detection limit in MS and UV might exceed the extracted amounts of the compounds.

En raison de leurs excellentes propriétés, les polyoléfines telles que le polypropylène et le polyéthylène sont largement utilisées dans des applications d'emballage alimentaire. Cependant, tout au long de leur cycle de vie ou de la première utilisation, les polyoléfines peuvent être exposées à des milieux contaminés qui limitent leur recyclabilité en contact alimentaire. Par conséquence, le recyclage de polyoléfines au contact alimentaire nécessite des niveaux de décontamination rigoureux et donc une technologie de décontamination avancée. L’objectif de ce travail consiste dans un premier temps à étudier la faisabilité et la potentialité de l’extraction par CO2 supercritique en mode batch pour la purification de polyoléfines (extraction d’additifs et de contaminants modèles). On s’est plus particulièrement attaché à étudier l’effet des paramètres du procédé sur la cinétique de l’extraction ainsi que l’influence de l’extraction supercritique sur les comportements rhéologique et thermique des matériaux purifiés. Dans un deuxième temps, on s’est intéressé au développement d’un nouveau procédé continu d’extraction par couplage de l’extraction supercritique et l’extrusion bi-vis. Les résultats les plus importants ont montré la potentialité de l’extraction par CO2 supercritique en mode batch pour la purification de polyoléfines sans influencer significativement les propriétés de la matrice / Due to their excellent properties, polyolefins such as polypropylene and polyethylene are widely used in food packaging applications to preserve and protect foodstuffs. However, throughout their lifecycle or first use, polyolefins can be exposed to contaminated media which limit their recyclability in food contact applications. Therefore, the recycling of polyolefins into direct food contact applications requires rigorous decontamination levels and thus effective and advanced recycling technology. The objective of this work is, at first hand, to study the feasibility and the potential of supercritical CO2 extraction in batch process for the purification of polyolefins (extraction of additives and model contaminants). In the whole, we investigated the effects of process parameters and contaminant structure on the extraction kinetic, and the influence of the supercritical CO2 extraction on the rheological and thermal behaviors of the purified materials. On the other hand, we aimed at the development of a novel continuous extraction process by coupling supercritical extraction technique and twin-screw extrusion. The most significant results showed the potential of supercritical CO2 extraction in batch mode for the purification of polyolefins without influence significantly the matrix properties

No description available.

This work investigates the influence of microstructure and cooling and heating rates on the physical and chemical properties of fast crystallizing polymers. The primary objectives were to 1) utilize advanced methodologies to accurately determine the fundamental thermodynamic value of equilibrium melting temperature (Tmo) for the semi-crystalline polymer poly(ether ketone ketone) (PEKK), 2) increase understanding of the influence of microstructure (random versus blocky) of functionalized semi-crystalline polymers on physical and chemical properties, and 3) understand the influence of additive manufacturing process parameters on semi-crystalline polymer crystallization and final properties. All objectives utilized the advanced characterization technique of fast scanning calorimetry (FSC) using the Mettler Toledo Flash DSC 1. The first half of this work focuses on the high-performance semi-crystalline aromatic polymer poly(ether ketone ketone) (PEKK) with a copolymerization ratio of terephthalate to isophthalate moieties (i.e., T/I ratio) of 80/20. Due to the fast heating and cooling rates of the Flash DSC, PEKK underwent melt-reorganization upon heating at slow heating rates. This discovery resulted in utilizing a Hoffman-Weeks linear extrapolation of the zero-entropy production temperature to establish a new equilibrium melting temperature of 382 oC. Additionally, a new NMR solvent, dichloroacetic acid, was discovered for PEKK, allowing for comprehensive NMR analysis of PEKK for the first time. Diphenyl acetone (DPA) was discovered as a novel, benign gelation solvent for PEKK, enabling heterogeneous gel-state bromination and sulfonation to afford blocky microstructures. The gel state functionalization process resulted in a blocky microstructure with runs of pristine crystallizable PEKK retained within the crystalline domains, and amorphous domains containing the functionalized PEKK monomers. The preservation of the pristine crystalline domains resulted in enhanced physical and chemical properties compared to the randomly functionalized analogs. Additionally, heterogeneous gel state functionalization of PEKK gels prepared from different solvents and gelation temperatures resulted in differences in crystallization behavior between blocky microstructures of the same degree of functionalization. This result demonstrates that the blocky microstructure can be tuned through controlling the starting gel morphology. The second half of this work focuses on understanding the influence of cooling and heating rates on the melting, crystal morphology, and crystallization kinetics on isotactic polypropylene (iPP), iPP-polyethylene copolymers (iPP-PE), and iPP/iPP-PE blends and using this information to gain understanding of how these polymers crystallize during the additive manufacturing processes of powder bed fusion (PBF) and material extrusion (MatEx). The crystallization kinetics of iPP, iPP-PE copolymers, and iPP/iPP-PE blends exhibited bimodal parabolic-like behavior attributed to crystallization of the mesomorphic crystal polymorph at low temperatures and the α-form crystal at high temperatures. Incorporation of non-crystallizable polyethylene fractions both covalently and blended as a secondary component, resulted in decreasing crystallization rates, inhibition of crystallization, and decreased crystallizability. Additionally, the non-isothermal crystallization behavior of these systems shows that the non-crystallizable fractions influence the crystal nucleation density and temperature at which polymorphic crystallization occurs. Utilizing in-situ IR thermography in the PBF system, the heating and cooling rates observed for a single-layer PBF print were used to mimic the PBF process by FSC. Partial melting in the printing process leads to self-seeding and increased crystallization onset temperatures upon cooling, which influences the final part melting morphology. Nucleation from surrounding powder and partially melted crystals greatly influences the crystallization kinetics and crystal morphology of the final part. Utilizing rheological experiments and process-relevant cooling rates observed in the MatEx process, the miscibility of iPP/iPP-PE blends influenced the nucleation behavior and crystallization rates, subsequently leading to differences in printed part properties. / Doctor of Philosophy / The crystalline morphology of semi-crystalline polymers depends on their microstructure and thermal history. The resultant crystalline morphology greatly affects the physical and chemical properties. In the first part of this work, the effect of microstructure on material properties is explored. Block copolymer microstructures consist of two or more blocks of distinct polymer segments covalently bonded to one another. This leads to self-organization of the components into unique structural order that would not be attainable if the polymer segments were randomly bonded together. This structural order enhances material properties; thus, block copolymers are advantageous for many applications. However, synthesis of block copolymers can be tedious and expensive. Thus, additional methodologies for block copolymer synthesis are desired. In this work blocky (i.e., statistically non-random) copolymers are synthesized through a facile post-polymerization functionalization method. These blocky copolymers result in enhanced physical and chemical properties compared to the randomly synthesized analogs. This work shows blocky functionalization of a new polymer under new post-polymerization conditions and expands upon the synthesis methodology for block copolymers. In the second part of this work, the effect of heating and cooling rates on the formation of crystals during additive manufacturing is explored. Additive manufacturing modalities of powder bed fusion and material extrusion consist of rapid heating and cooling processes, which can affect how crystals form and ultimately affect the final printed part properties. Using a technique called fast scanning calorimetry, the different heating and cooling rates that the polymer witnesses during printing can be mimicked, and the formation of crystals under these different conditions can be replicated. This mimicking analysis can be related to the printing process and be used to help guide printing processes to enhance printed part properties.

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