Dissertations / Theses on the topic 'Diene polymere'

We demonstrate a novel and ready to prepare thermoreversible hetero Diels–Alder dilinker on the basis of dithiooxalates, enabling the mild, rapid and catalyst-free linkage of diverse diene species under ambient conditions for applications in the fields of, for example, modular ligation, self-healing or recyclable materials and surface modification amongst others. The linker was studied using quantum chemical calculations, and experimentally in small molecular reactions via UV/Vis spectroscopy, mass spectrometry and NMR as well as in step-growth polymerizations with diene-difunctional building blocks – characterized via (temperature dependent) SEC and HT NMR – as an example for efficient polymer ligation.

Cette thèse se divise en trois parties. La première concerne le développement d'une nouvelle voie d'accès à des hétérocycles azotés. Cette synthèse est basée sur deux étapes: l'addition radicalaire d'un xanthate, portant une fonction 1,2-dione, sur diverses oléfines suivie de sa condensation sur une diamine. Cette étude a permis de préparer des composés présentant un intérêt biologique certain tels que des pyrazines. De plus, une nouvelle méthodologie permettant l'accès à des structures imidazoles a été mise en évidence. La seconde partie a été consacrée à la préparation d'un support soluble à l'aide du procédé Madix. La dernière étude porte sur le développement de nouveaux agents modérateurs de la polymérisation radicalaire. Cette étude nous a amenés tout d'abord à synthétiser une large gamme de composés originaux de type dihydro-pyrazolone. Par la suite, la mise en place d'une étude modèle nous a permis de mesurer l'aptitude à se dissocier de ces composés puis de sélectionner les meilleurs candidats. Enfin, une étude poussée en polymérisation des agents sélectionnés a permis de mieux comprendre leur mécanisme d'action. Nous sommes en présence d'un système de type initer original. Ce système de polymérisation n'est cependant pas vivant du fait de l'irréversibilité de l'addition du contre radical dihydro-pyrazolone sur la chaîne polymère.

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A reciclagem de refugos é um processo estratégico que viabiliza a expansão do mercado de plásticos, podendo gerar novos produtos. A obtenção de blendas poliméricas é uma alternativa nesse processo, já que é conhecida a perda de propriedades mecânicas dos termoplásticos nas etapas de reprocessamento. Neste trabalho, o polietileno de alta densidade (PEAD) reciclado teve adições de borracha do monômero etileno-propileno-dieno (EPDM) puro em baixos teores (1 %, 5 % e 10 %), cujo objetivo foi formar blendas miscíveis e um produto final mais resistente ao impacto. O PEAD foi submetido a quatro ciclos de moagem, extrusão e injeção (reprocessamento) e misturado ao EPDM puro por extrusão sem o uso de qualquer aditivo. Os grânulos da blenda formada foram usados para confeccionar os corpos-de-prova por injeção para seu uso nas distintas metodologias analíticas. O processo de irradiação gama foi aplicado nas doses de 50 kGy e 100 kGy e os parâmetros físico-químicos e mecânicos dessas amostras foram comparados aos das não irradiadas. Tanto as blendas irradiadas como as não irradiadas mostraramse visualmente e microscopicamente homogêneas, indicando a compatibilidade da mistura, que também é verificada por seu comportamento térmico. Os parâmetros mecânicos provenientes dos ensaios de tração e flexão, foram semelhantes nas amostras do termoplástico virgem e do reciclado; o processo de irradiação nas blendas gerou sua reticulação, sendo esta verificada não só pelo aumento dos valores desses parâmetros como também pelo aumento da fração gel. A resistência ao impacto aumentou cerca de duas vezes e meia nas amostras com maior teor de EPDM e cerca de 6 a 7 vezes nestas mesmas amostras irradiadas a 50 kGy e 100 kGy respectivamente. O novo material obtido tem fortes indicativos para a sua utilização na pequena e média indústria de plástico, uma vez que já com 1 % de EPDM apresentam melhores características mecânicas em relação ao termoplástico reciclado quatro vezes e essas características foram incrementadas após o processo de irradiação gama.
Dissertação (Mestrado em Tecnologia Nuclear)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Un des défis majeurs du 21ème siècle sera l'économie d'énergie, c'est pourquoi nous recherchons actuellement la plus grande efficacité du matériel et des procédés industriels, couplée à une économie en énergie. La chimie organique moderne n'échappe pas à ce constat et doit en plus fournir les besoins croissants de nouvelles molécules dans le domaine pharmaceutique, l'agrochimie ainsi que la recherche de nouveaux matériaux. L'utilisation de catalyseur à base de métaux de transition a permis de limiter les étapes de synthèse, de diminuer les quantités de réactifs ainsi que d'augmenter l'efficacité des procédés, et donc de réaliser ces économies. De plus, les précurseurs catalytiques, notamment à base de ruthénium, ont permis de créer de nouvelles combinaisons qui ne sont pas permises par les systèmes dit classiques. La transformation d'alcynes catalysée au ruthénium est un outil puissant nous permettant d'accéder en peu d'étapes de synthèse à des molécules polyfonctionnelles. La synthèse de dérivés 1-halo-1,3-diéniques a été réalisé par dimérisation d'alcynes et addition concomitante d'un proton et d'un halogénure. Ces dérivés sont intéressants et pourront être utilisés comme synthon, car de par la présence d'halogènes, les fonctionnalisations et l'incorporation de l'unité 1,3-diènique à des structures plus complexes sont possibles. L'addition d'un halogènure d'hydrogène sur différents alcynes représente la voie de synthèse la plus économique d'un point de vue atomique pour la préparation d'halogénures de vinyles. La catalyse au ruthénium permet d'effectuer cette réaction à température ambiante. Enfin, en appliquant la dimérisation d'alcynes aux diynes, de nouveaux matériaux photoluminescents ont été synthètisés par catalyse au ruthénium
One of great challenges of this new century will be energy saving. In this order we are looking the most efficient and energy saving equipments and industrial processes. Modern organic chemistry is not an exception, and has to develop more and more molecules to the needs of pharmaceutical, agrochemical and the search for new materials. Shorter synthesis, less quantity of reactants and increased efficiency of reactions can be done by the use of catalyst based on transition metals. Moreover, new reactions have been discovering by the use of catalysts based on transition metal, in particular with catalysts based on ruthenium. This thesis describes the development of new reactions to synthetize complex products from simple reactant as alkynes, by the use of ruthenium-based catalyst. In the first chapter, an efficient, novel and direct access to 1-halo-1,3-butadienes is developed. This stereoselective ruthenium-catalysed reaction proceeds under mild conditions via the head-to-head oxidative coupling of two alkynes and a concomitant hydrohalogenation. In the second chapter, the synthesis of vinyl halide derivatives is developed. The reaction proceeds very fast at room temperature via the Markovnikov addition of hydrogen halide to alkynes. In the third chapter, by application of dimerisation of alkynes to diynes, access to new π-conjugated polymers is developed. UV-visible absorption and emission properties of these polymers will be exposed

The direct catalytic hydrogenation of nitrile butadiene rubber (NBR) in latex form was studied as a model system for the development of a new latex hydrogenation process for the modification of unsaturated diene-based polymers. NBR is a synthetic rubber of copolymerized acrylonitrile and butadiene produced in latex form by emulsion polymerization. The catalytic hydrogenation of NBR is an important post-polymerization process resulting in a more stable and tougher derivative, hydrogenated NBR (HNBR), which has been widely used in the automotive and oil drilling industry. The present commercial process involves a number of cumbersome steps to obtain solid NBR from the latex and subsequent dissolution of the solid NBR in a large amount of organic solvent followed by solvent recovery after coagulation of the hydrogenated NBR. Since NBR is produced in latex form, it is very desirable to directly hydrogenate NBR in the latex form which will significantly simplify the hydrogenation process and facilitate subsequent applications. As an economical and environmentally benign alternative to the commercial processes based on the hydrogenation of NBR in organic solution, this direct latex hydrogenation process is of special interest to industry. The objective of this project is to develop an efficient catalytic system in order to realize the direct catalytic hydrogenation of NBR in latex form. OsHCl(CO)(O2)(PCy3)2 was initially used as the catalyst to investigate the possibility of hydrogenation of NBR in latex form and to understand the major factors which affect the hydrogenation operation. It was found that an organic solvent which is capable of dissolving or swelling the NBR was needed in a very small amount for the latex hydrogenation using the Os catalyst, and gel occurred in such a catalytic system during hydrogenation. Wilkinson’s catalyst, RhCl(PPh3)3, was then used for the latex hydrogenation in the presence of a small amount of solvent successfully without gel formation. Further investigation found that Wilkinson’s catalyst has a high activity for NBR latex hydrogenation without the use of any organic solvent. The influences of various operation conditions on hydrogenation rate, such as catalyst and polymer concentrations, latex system composition, agitation, reaction temperature and hydrogen pressure, have been investigated. It was found that the addition of triphenylphosphine (TPP) has a critical effect for the hydrogenation of NBR latex, and the hydrogenation rate was mainly controlled by the amount of catalyst which diffused into the polymer particles. In the presence of TPP, NBR latex can be hydrogenated to more than 95% degree of hydrogenation after about 30 hours at 160oC using Wilkinson’s catalyst with a catalyst to NBR rubber ratio of 1 wt%, without the addition of any organic solvent. The apparent activation energy for such NBR latex hydrogenation over the temperature range of 152oC to 170oC was found to be 57.0 kJ/mol. In the present study, it was also found that there are some impurities within the NBR latex which are detrimental to the hydrogenation reaction and are suspected to be water-soluble surfactant molecules. Deliberately designed solution hydrogenation experiments were conducted to study the impurity issue, and proper latex treatment methods have been found to purify the latex before hydrogenation. To improve the hydrogenation rate and to optimize the latex hydrogenation system, water soluble RhCl(TPPMS)3 catalyst (TPPMS: monosulphonated-triphenylphosphine) was used for the latex hydrogenation of NBR. The latex hydrogenation using the water soluble catalyst with TPP can achieve more than 90% degree of hydrogenation within 20 hours at 160oC. Further experiments using RhCl3 with TPP proved that the water soluble RhCl3 can be directly used as a catalyst precursor to generate the catalytic species in situ for the latex hydrogenation, and a stable NBR latex with 96% degree of hydrogenation can be produced without any gel problem within 19 hours of reaction at 160oC. The catalyst mass transport processes for these Rh based catalysts in the latex system were investigated in order to further optimize the solvent-free latex hydrogenation process. While maintaining the emulsified state of the original latex, the direct catalytic hydrogenation of NBR latex can be carried out efficiently without any cross-linking problem to more than 92% degree of hydrogenation within 8 hours at 160oC. As a result of this research project, new latex hydrogenation technologies were successfully developed to fulfill all major requirements for a solvent-free polymer latex hydrogenation route, which is a significant milestone for the improvement of this polymer modification technology. The finding of TPP’s role as the “catalyst mass transfer promoter” is a breakthrough for the research field related to the hydrogenation of unsaturated diene-based polymers in latex form.

碩士
國立交通大學
材料科學與工程學系
99
In this thesis, we fabricated devices with four novel main chain donor -acceptor conjugated polymers, named PT6TPD,PT8TPD,PCPDTTPD, and PDTSTPD. Because of the presence of the electron-deficient thieno[3,4-c]pyrrole-4,6-dione (TPD) moieties, these polymers exhibited an excellent thermal stability, crystalline characteristics, a broad spectral absorption, and a low-lying HOMO energy level—all features that are desirable for solar cell applications. In order to obtain good performance of the solar cells, fabricating methods and parameters have to be processed carefully, including the choice of solvent, the blending composition between polymer and fullerene, the temperature and time of heat treatment, substituting PC71BM over PCBM, and the choice of additive. All the processes could affect the morphology of active layer, and lead to better power conversion efficiency. Modulating the morphologies of the blends allowed us to optimize devices based on these polymer:PC71BM blends. All the optimized blends were dissolved in DCB and annealing at 90℃ for 20 minutes. The solar cell devices prepared by PT6TPD, PT8TPD, and PDTSTPD blended with PC71BM at a ratio of 1:1 and processed with 4 vol% DIO exhibited power conversion efficiency of 2.56%, 2.21%, 3.45%, separately. Another device incorporating PCPDTTPD and PC71BM (blend weight ratio, 1:4), with 3 vol% CN exhibited power conversion efficiency of 2.15%.

Hydrogenated nitrile butadiene rubber (HNBR) which is known for its excellent elastomeric properties and mechanical retention properties after long time exposure to heat, oil and air is produced by the catalytic hydrogenation of nitrile butadiene rubber (NBR). Hydrogenation of NBR is carried out preferably in solution via homogeneous catalysis. As yet, it is being commercially produced in a semi-batch process where gaseous hydrogen continuously flows into a batch of reactant polymer. Several catalysts have been exploited successfully for the hydrogenation of NBR in organic solvents, which include palladium, rhodium, ruthenium, iridium and osmium complexes. Owing to the drawbacks of batch production (such as time taken for charging and discharging the reactants/products, heating and cooling, reactor clean up), and the huge demand for HNBR, a continuous process is proposed where potential time saving is possible in addition to the high turn over of the product. Numerical investigation of the HNBR production in a plug flow reactor and a continuous stirred tank reactor showed that a reactor with plug flow behavior would be economical and efficient. A static mixer (SM) reactor with open-curve blade internal geometry is designed based on the simulation and hydrodynamic results. The SM reactor was designed with 24 mixing elements, 3.81 cm ID and 90 cm length. The reactor has a jacket in which steam is used to heat the polymer solution. The hydrodynamics in the SM reactor (open-flat blade structure) with air-water system showed that plug flow could be achieved even under laminar flow conditions (Reh < 20). For a constant mean residence time, the Peclet number was varying such that it is 4.7 times the number of mixing elements (ne) used in the SM reactor. Empirical correlations were developed for gas hold up (εG) and overall mass transfer coefficient (KLa). The mass transfer experiments showed that high KLa, 4 to 6 times compared to that of the conventional reactors could be achieved in the SM reactor at particular operating conditions. Very important information on the Peclet number, liquid hold were obtained from the hydrodynamic experiments conducted with the actual working fluids (hydrogen, polymer solutions) in the SM reactor. The superficial gas velocity had an adverse effect on both Peclet number and liquid hold up. The viscosity of the polymer solution also had a marginal negative effect on the Peclet number while a positive effect on the liquid hold up. The hydrogenation performance with the homogeneous catalyst OsHCl(CO)(O2)(PCy3)2 was performed in the continuous process with SM reactor. Complete hydrogenation of NBR was possible in a single pass. The effect of mean residence time, catalyst and polymer concentration on the final degree of hydrogenation was studied. The minimum catalyst required to achieve degree of hydrogenation over 97% was empirically found and an empirical correlation was developed for degree of hydrogenation as a function of operating conditions and parameters. Hydrogenation in the SM reactor is modeled by using plug flow with axial dispersion model that is coupled with the concentrations of carbon-carbon double bond, hydrogen and osmium catalyst. The model involves coupled, non-linear partial differential equations with different dimensionless parameters. The proposed model was verified with the experimental results obtained from the hydrogenation and hydrodynamic experiments. The model could satisfactorily predict the degree of hydrogenation obtained from experimental results at various operating conditions. In general, the designed continuous process with SM reactor performed well and was an effective method of manufacturing HNBR on a continuous basis. The designed system is amicable to the industrial operating conditions and promises to be highly efficient and economic process for production of HNBR.

碩士
國立交通大學
材料科學與工程學系
99
In this thesis, a series of donor-acceptor (D–A) conjugated polymers, PBTTPDs, containing electron-withdrawing thieno[3,4-c]pyrrole-4,6-dione (TPD) and electron-donating bi(alkyl)thiophene units were synthesized. We also prepared two TPD based low band-gap polymers, PCPDTTPD and PDTSTPD, conatining electron-donating cyclopenta[2,1-b;3,4-b′]dithiophene (CPDT) and dithieno[3,2-b:2′,3′-d]silole (DTS) units. The PBTTPD based polymers exhibit high crystalline characteristics, low-lying HOMO energy level, and excellent thermal properties. Bulk heterojunction (BHJ) photovoltaic devices incorporating these polymers/ [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend displayed good photovoltaic properties. Especially, the PBTTPD1 based device displayed a high power conversion efficiency (PCE) of 4.7%. Moreover, both of PCPDTTPD and PDTSTPD exhibit low band-gap properties (1.74 and 1.69 eV, respectively) and excellent thermal properties. BHJ photovoltaic devices incorporating PCPDTTPD/[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) and PDTSTPD/PC71BM blends displayed PCEs of 1.0% and 1.6%, respectively. Furthermore, when incorporating small amount of additives into these blends, their PCEs of devices were enhanced to 3.1% and 2.7%, individually, because of their smoother and more homogeneous morphology of the blend.

碩士
國立臺北科技大學
有機高分子研究所
105
In this work, two novel conjugated polymers with diketopyrrolopyrrole (DPP) as electron-withdrawing blocks, which possess strong light-harvesting ability in UV-visible region, were designed, synthesized and characterized. Moreover, the DPP unit has a narrow bandgap and high carrier mobility that is beneficial for improving the photovoltaic properties of bulk-heterojunction solar cells. In order to enhance the solubility of final products, the DPP unit was firstly functionalized with an alkyl chain through the nitrogen atom and were capped with octyldodecyl thiophene at both ends. After the addition of Louis acid, the special functionalized alkyl chain groups were deprotected to form a fused DPP unit, which is called an π-expanded DPP. Then, two different donor units, 3,3-Difluoro-[2,2-bithiophene]-5,5-diyl)bis(trimethylstannane and 9-(heptadecan-9-yl)-2,7 bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole, were used to co-polymerize with π-expanded DPP by Stille coupling reaction and Suzuki coupling reaction, respectively. The molecular weight characteristics and optical properties of these polymers were examined using GPC and UV-vis spectra, respectively. Furthermore, the XRD and AC-2 techniques were employed to determine the crystallinity and HOMO levels of the new polymers.

碩士
臺灣大學
藥學研究所
95
Hepatitis C virus (HCV) has become a serious etiological agent worldwide. HCV sets up a persistent infection in 70-80% of cases, and can lead to cirrhosis or hepatoma. Currently available interferon-based treatments show limited efficacy. Therefore, to develop new and more effective therapies is a vital and urgent issue. WSP-9376 was discovered as an HCV helicase inhibitor (IC50 = 20 uM) in our laboratory through computational virtual screening using the DOCK program. Coincidentally, this compound was found as an HCV NS5B polymerase inhibitor (IC50 = 44.5 uM) as well, thus being selected as our lead. When it comes to both potency and selectivity toward HCV, NS5B RNA-dependent RNA polymerase (RdRp) can be a proper target. Since it is essential for HCV RNA polymerization and there is no functional counterpart in mammalian cells. Five binding sites of NS5B, four allosteric binding sites and the active site, are commonly reported. Most of the active site inhibitors belong to nucleoside analogues (substrate-like) or pyrophosphate-mimics (product-like). On the contrary, numerous classes of structurally diversified allosteric inhibitors have been developed. By employing scaffold hopping strategies, four series of compounds were designed whereas only one was fulfilled in synthesis, i.e. 3-arylmethylene-1H-quinoline-2,4-diones. Among them, compound 44b is the most potent NS5B inhibitor with an IC50 of 8.4 uM against NS5B. Albeit there is only slight improvement in the inhibitory activity of 44b compared with the lead, it is more important that we have identified this core structure for the development of new NS5B inhibitor, even if the structure differs a lot from that of WSP-9376. Moreover, the binding site of this series of compounds may be the active site, since compound 44b has been shown to have influence to some extent on the substrates of NS5B. In other words, this is probably another series of active site inhibitors distinguished from those published previously.

碩士
國立交通大學
材料科學與工程學系
99
In this thesis, we have synthesized a conjugated polymer containing electron-withdrawing thieno[3,4-c]pyrrole-4,6-dione (TPD) and electron-donating thieno[3,4-c]pyrrole-4,6-dione units (TT), PTTTPD. We also synthesized TPD based low band-gap polymers conatining electron-donating 4-(heptadecan-9-yl)-4H-dithieno[3,2-b:2',3'-d] pyrrole (DTP), PDTPTPD. Besides, we also intrduced the thiophene as the spacer between donor and acceptor, and then we synthesized PDTTTPD and PDTPDTTPD. The PTTTPD and PDTTTPD exhibited high crystalline characteristics and excellent thermal properties. Bulk heterojunction (BHJ) photovoltaic devices of PDTTTPD incorporating [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) and 1% DIO, than it displayed high power conversion efficiency (PCE) of 5.1 %. But the devices of PTTTPD didn’t, it just only 0.25 %. Moreover, both of PDTPTPD and PDTPDTTPD exhibited low band-gap properties and excellent thermal properties. BHJ photovoltaic devices of PDTPTPD and PDTPDTTPD incorporating PCBM and they displayed PCEs of 1.86 % and 0.76 %, respectively. Furthermore, when the devices of PDTPDTTPD incorporating with small amount of additives into these blends, the PCE of PDTPDTTPD were enhanced to 1.16 %.

博士
國立清華大學
化學系
88
Abstract In this thesis, we designed novel photo-degradable polymers and developed a new method for their synthesis. These new materials contain a silyl group, which can control the photodegradability. Furthermore, the derivatives of nordihydroguaiaretic acid (NDGA) were synthesized and results from experiments and computations indicate that tetraglycinylated NDGA 4 HCl (G4N) could function as a new class of anti-HIV agents. In Part 1 of this thesis, a series of silicon-containing poly(butadienes) was synthesized in two steps, which involve nitration of poly(butadienes) by use of sodium nitrite and ceric ammonium nitrate (CAN) followed by the silicon-promoted Nef reaction. The results of photo-degradation efficency indicate that introduction of a b-(triorgano)silyl ketonic unit ((-CH(CH2SiR3)C(=O)-) into poly(butadienes) allowed dramatic improvement on their photo-degradability. In Part 2, new N-phenyl aromatic polyureas containing bis[(N,N''-diphenyluredio)methyl]silane units (-[HNC(=O)NPhCH2SiMe2CH2NPhC(=O) NH]-) in the skeleton were designed as a new type of photo-degradable polymers. The mechanistic studies indicate that both of the Si-CH2N bonds in the bis[(N,N''-diphenylureido)methyl]silane unit were cleaved through sequential single electron transfer, silyl group migration, and solvolysis. In Part 3, the treatment of NDGA with N,N-dimethylglycine in the presence of dicyclohexylcarbodiimide and a catalytic amount of dimethylaminopyridine in CH2Cl2. The resultant tetraglycinylated NDGA was allowed to react with HCl(g) in situ to give the corresponding tetraglycinylated NDGA 4 HCl (G4N). G4N has a suitable geometry and binding sites for interacting with GC Box DNA through the major groove as revealed by the computational analysis. Use of the fluorescence and the UV techniques in combination provided the apparent binding constants (Kapp). Our results indicate that G4N can effectively bind DNA. Under pH 5.0 buffer solution, G4N showed greater binding ability.