ANALYSIS OF POLYMERS

Author: GUMI CABALLERO TANIA.
Year: 2004.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: ESCUELA DE POSTGRADO.

Summary: The separation systems offer great advantages through membranes respect traditional separation methods. For this reason, four different types dem embranas: supported liquid membrane (SLM) composite membranes activated (ACM), activated chiral membrane (CAM) and membranes based polisulfora chiral (SPC) have been developed and applied to the separation enantiomérico drug propanol. The results have revealed the mechanisms of separation / transportation system involved in the study. His behavior has been characterized and optimized. It has succeeded in transporting enantioselectivo and therefore separation (partial) of the enantiomers of drug propanol.

Author: DOMÍNGUEZ ESPINOSA GUSTAVO NOEL.
Year: 2005.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Dep. Termodinamica Aplicada.
Place of preparation: Universidad Politécnica de Valencia.

Summary: It has studied the influence of the chemical structure of polymers in their behavior relajacional. The experimental techniques were dielectric spectroscopy broadband and flows depolarization thermally stimulated. It has been studied on the one hand the relajaciones below the glass transition temperature, and on the other hand, the evolution of the processes above the glass transition. For the study of relajaciones sub-vítreas technique flows thermally stimulated depolarization was used as a fundamental tool in the study of processes relajacionales. This technique has been supplemented with measurements made using spectroscopy and theoretical calculations impedances of molecular mechanics. In chapter 2 is conducting a study with methacrylates of metil-ciclohexilo, varying the position of the methyl group in anillo.En Chapter 3 presents the study of a series of polymers itacónicos di-substituted by methyl ester group, etilos, propilos and ciclo-hexilos. In chapter 4, presents a study of the processes relajacionales above the glass transition. La técnica experimental principal ha sido la espectroscopia dieléctrica de banda ancha, y como técnica de apoyo se ha utilizado las corrientes de despolarización térmicamente estimuladas. For greater separation processes has been used a mathematical tool for the investment of data permitivity dielectric distribution of delay times. The main purpose of this chapter is to see how the processes are superimposed on high temperatures and the influence of chemical structure of the polymers is on the overlap.

Author: CERVELLERA PIÑOL ROSER.
Year: 2005.
University: ROVIRA I VIRGILI [www.urv.cat].
Place of defense: FACULTAT DE QUIMICA.
Place of preparation: FACULTAT DE QUIMICA.

Author: FERRANDO LEBRAUD HARITZ EDER.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA [www.upc.edu].
Place of defense: Sala de Conferències de l'ETSEIAT.
Place of preparation: ETSEIB, PAVELLÓ E Campus SUD.

Author: CANADELL AYATS JUDIT.
Year: 2006.
University: ROVIRA I VIRGILI [www.urv.cat].
Place of defense: FACULTAT DE QUIMICA.
Place of preparation: FACULTAT DE QUIMICA URV.

Summary: Over the past few decades, the polymeric materials have been replacing conventional materials because they are more versatile, less dense and have interesting properties. However, it also presents some limitations. One is its inherent combustibility so in the presence of a heat source and oxygen are burned easily and quickly. The problem is not just the loss of material properties, but the smoke and toxic gases that are released are the main perpetrators of the danger of a fire. Another of the limitations is that during curing, suffer a contraction leading to the tensions that eventually produces mechanical fatigue and the possible appearance of cracks and breaks, in addition to producing a loss of adherence to other components. Among the various strategies to get the flame resistant materials are incorporating loads (additives), or modifying the chemical structure and the synthesis of polymers specific (reactive). Although the use of additives is the method most widely known industry-wide for economic reasons, it presents some drawbacks, and can be extracted with solvents, can migrate and can impair the properties of the material. The chemical modification of the material to give fire-retardant properties, either through polymerization of monomers containing the atom responsible for the fire resistance or subsequent polymer allows solve the aforementioned problems of additives. Although there are different heteroelementos that can be used as a flame retardant on the blaze, the market is still dominated by the use of halogenated compounds. These compounds that are highly effective, interfering with the reactions responsible for the spread of the flame presented as inconvenience during combustion releases toxic gases and corrosive. For this reason, in recent years has increased interest in the search for flame retardants to halogen-free, which are more respectful of the environment and less aggressive in the event of a fire. The compounds containing phosphorus and silicon have proved effective flame retardants to more environmentally. The second drawback of the aforementioned contraction during curing, it is especially important for the electronics industry, which needs materials capable of cure with a low shrinkage not deteriorate for the components. To reduce shrinkage during curing, at present, the most commonly used method is the addition of loads. This method has the disadvantage of increasing the viscosity of the resin, which makes it difficult to process and leads to a material more rigid and fragile. One possible solution to the above problems is the use of "expandable monomers" those who do not suffer during the curing contraction, or even expand, for example the espiroortoésteres (SOEs). Against this background, what is proposed in this paper is the development of new polymeric materials submitted properties retardancia to the flame through the introduction of phosphorus and silicon and also submit a low shrinkage during curing and curing using SOEs. To achieve the goal have developed various strategies that will be presented briefly below: 1. Synthesis of new monomers based espiroortoésteres containing phosphorus or silicon in its structure. Specifically, have synthesized two espiroortoésteres phosphorus, propanoate 1,4,6-trioxaespiro [4.4] nonano-2-il) -metil-3- [10-(9,10-dihidro-9-oxa-9- fosfafenantreno-10-óxido-10-il)] and maleate bis [(1,4,6-trioxaespiro [4.4] nonano-2-il) -metil 2-[10-(9,10-dihidro-9- oxa-9-fosfafenantreno- 8 10-óxido bba)] and one sililado, propanoate 1,4,6-trioxaespiro [4.4] -2-nonilmetil 3-trimetil silil. These new monomers are obtained in good yields by esterification reaction or an addition of Michael. The espiroortoésteres precursors were obtained from the traditional method, ie from the reaction of the -butirolactona with an epoxide in the presence of a Lewis acid. It has been studied polymerization and copolymerization of these espiroortoésteres with epoxy resins business with triflato ytterbium as a starter. The monitoring of the reactions has been carried out by differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR / TPA). The properties of the material in the final materials have been evaluated through DSC, thermogravimetric analysis (TGA) and analysis termodinamomecánico (DMTA). The shrinkage of materials has been determined from the actions of densities with a picnómetro helium and properties retardancia to llamA have been evaluated from the measures limiting oxygen index (LOI). In addition, it also has studied the effect of combining phosphorus and silicon in the same material, in order to investigate a possible synergy between the two elements. 2. Synthesis of new polymers that contain phosphorus and groups espiroortoéster in the side chain, through copolimerizaciones radicalarias a espiroortoéster containing a group in its structure and acrylate monomers different phosphorus. These new polymers have been interlocked subsequently triflato ytterbium as cationic initiator, through the double opening of espiroortoésteres. It has also investigated the copolymerization cationic between the linear polymer containing a espiroortoéster in the side chain and various epoxy resins. Using epoxy resins fosforadas previously synthesized in the laboratory, has been introduced phosphorus in the final materials, and thus improve the properties of retardancia the flame. 3. Finally, we have studied a new method of copolymerization of espiroortoésteres with epoxy resins using microwave radiation to accelerate this process, and has been compared to the results obtained by the conventional method of warming.

Author: SAINZ VAQUE RAQUEL.
Year: 2006.
University: ZARAGOZA [www.unizar.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: INSTITUTO DE CARBOQUIMICA.

Summary: This dissertation focuses on the development of new composite materials multifunctional taking as a basis a polymer driver, polianilina, and an infill Nanostructured, carbon nanotubes. It was looking for a synergistic interaction between the two components resulting in a set of materials with improved properties, such as conductivity, thermal stability, good mechanical properties, solubility in common organic solvents and, therefore, the possibility of processing materials in the form of films, fibers or coatings. In addition raised the use of different doping for polianilina with the goal of adding other features to the composite material as the optical activity. The thesis describes the synthesis of composite materials of polianilina as emeraldina salt and carbon nanotubes multiple layer, and transforming the way emeraldina basis. We studied the morphology and structural characteristics, thermal, optical and electrical materials, the mechanism of interaction between the carbon nanotubes and the polymer, as well as the possibility of solubility and processing the material in the form of films. The greatest achievement of this work was to obtain a composite material of carbon nanotubes wall and polianilina in multiple ways emeraldina basis. The composite material containing more than 50% by weight of nanotubes and 9 orders of magnitude more driver that emeraldina basis without carbon nanotubes, reaching at room temperature conductivity of 0.1 S / cm. What is more surprising is that this composite material, with such a high percentage of nanotubes, it is completely soluble in NMP. Obtaining solutions of composite material allows processing material in the form of films, fibers and coatings, and enables their use in industrial applications such as membranes, diodes, paints conductive, shielding interference, transistors, etc.. By doping with a chiral acid, (+) -HCSA, this composite material has been able to obtain the composite material with optical activity, which is soluble and can be further processed in the form of thin films. There have also been obtained composite materials with optical activity through polymerization "situ" in the presence of chiral dopante. The conditions of synthesis are of great importance in the characteristics of the material obtained, and they affect the properties of the resulting composites. The structure of the nanotubes used for the preparation of composite material is of great importance to ensure a good interaction between them and the polianilina. The presence of nanotubes electric arc in the composite material avoids deprotonación of polianilina and therefore the loss of optical activity over time. The potential applications of these materials include its use in asymmetric synthesis, chiral separations and chiral sensors. Moreover films obtained from the solutions of composite materials in NMP show some mechanical properties superior to those movies EB without nanotubes. In addition, MWNTs moving solvent (MPN) in the movies polianilina, avoiding the formation of H bridges between east and chains polianilina. As a result the glass transition temperature (Tg) moves to higher temperatures. In summary, the presence of carbon nanotubes in movies favors one hand, the mechanical properties of the same, with a large increase in the value of storage module, and on the other hand it reduces the amount of solvent in the films, indeed very beneficial to electronic applications because the more solvent be retained in the film polymer worst are s 8 us propi 557 ages electronic. The excellent results described in this report make the synthesis of composite materials of polianilina and carbon nanotubes is very promising to obtain highly functional materials and numerous industrial applications. The wide variety of conditions in the synthesis of polianilina, such as the use of different curing methods and the use of various doping and oxidizers, opens many possibilities in the future preparation of composite materials. The use of polymers other drivers as polipirrol, polythiophene or PmPV expand even more possibilities for synthesis and applications of composite materials of carbon nanotubes.