Orientador: Liliane Maria Ferrareso Lona / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T09:02:38Z (GMT). No. of bitstreams: 1 Nogueira_TelmaRegina_M.pdf: 1480628 bytes, checksum: 14c76a07ef8f486a5b1e73854f5c7634 (MD5) Previous issue date: 2008 / Resumo: Polimerização via radical livre controlada, também conhecida como "pseudoliving radical polymerization" tem recebido cada vez mais atenção como uma técnica para produção de polímeros com micro estrutura altamente controlada. Em particular, distribuições de pesos moleculares estreitas são obtidas, com polidispersidade muito próxima de um. Rotas convencionais para polímeros como estes têm sido polimerizações iônicas, no entanto, elas são extremamente sensíveis a impurezas e ao tipo de solvente. Processos de polimerização via radical livre, que são muito mais versáteis e robustos a impurezas, para a produção de polímeros com estruturas controladas via processo "controlado" ou "pseudo-living", têm se tornado uma importante alternativa. Como desvantagem do processo controlado aponta-se a baixa velocidade de reação quando comparada à polimerização convencional. A maioria dos trabalhos publicados sobre polimerização controlada via radicais nitróxido é feita considerando o estudo da homopolimerização de estireno. Neste projeto de pesquisa, é investigada, em nível experimental, a co-polimerização de estireno e divinilbenzeno (DVB) via polimerização controlada por nitróxidos (NMRP) usando 2,2,6,6- tetrametil-1-piperidinoxil (TEMPO) como controlador e tert-butilperóxido-2-etilhexil carbonato (TBEC) como iniciador. O DVB funciona como gerador de ramificações na cadeia polimérica, melhorando as propriedades do estireno como resistência a solvente e ao impacto. O TBEC foi utilizado em substituição a iniciadores mais convencionais como o 2,2-azo-bis-iso-butironitrila (AIBN) e peróxido de benzoíla (BPO), com o objetivo de acelerar a velocidade de reação, tentando manter o sistema controlado. Todos os experimentos foram feitos em ampolas. Para um melhor entendimento deste sistema, muitos experimentos foram realizados a diferentes temperaturas, concentrações de divinilbenzeno, concentrações de iniciador e razões molares entre as concentrações de controlador e iniciador. A conversão do monômero foi obtida por gravimetria e o polímero foi caracterizado através de Cromatografia de Permeação em Gel (GPC). Foi demonstrado que o TBEC foi capaz de aumentar a velocidade de reação em relação ao BPO e, em algumas condições operacionais utilizadas, polidispersidades próximas da unidade foram obtidas. / Abstract: Living free radical polymerization, also known as "pseudo-living radical polymerization" has received more and more attention as a technique for the production of polymers with micro structure highly controlled (narrow molecular weights distributions and polydispersity index close to one). Conventional routes to obtain polymer like this have been ionic polymerizations, however, they are extremely sensitive to impurities and solvents. Free radical polymerizations, which are more versatile and robust to impurities, for the production of polymers with controlled structures by "controlled" or "pseudo-living" process, have become an important alternative. As a disadvantage of the controlled process can be pointed the low reaction rate when compared to the conventional process. Most of the published papers about nitroxide mediated living free radical polymerization consider the homopolymerization of styrene as case study. In this research, the co-polymerization of styrene and divinylbenzene (DVB) by living free radical polymerization (NMRP) is investigated in experimental level. The stable radical used was 2,2,6,6-tetramethyl-1-piperidinoxyl (TEMPO). The initiators used in this work were tertbutylperoxy- 2-ethylhexyl carbonate (TBEC) and benzoyl peroxide (BPO). DVB acts as a branching generator, improving the properties of the styrene as the solvent and impact resistance. TBEC was used in substitution to conventional initiators as 2, 2-Azo-bisisobutyronitrile (AIBN) and BPO, with the aim of accelerating the reaction rate, trying to keep a controlled/living system. All the experiments were performed in ampoules. To better understand this system, many experiments were performed at different temperatures, divinylbenzene concentrations, initiator concentrations and molar ratios between controller and initiator. Conversion was obtained by gravimetric method and the polymer was characterized by Gel Permeation Chromatograph (GPC). It was observed that, at certain operating conditions, the TBEC initiator was able to produce copolymers with polydispersity close to unity in a much faster velocity when compared to BPO. / Mestrado / Processos Quimicos / Mestre em Engenharia Química

Orientador: Liliane Maria Ferrareso Lona / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-22T15:50:54Z (GMT). No. of bitstreams: 1 Galhardo_Eduardo_D.pdf: 4095854 bytes, checksum: db42fb4f8c74ed793863b10935db7dcd (MD5) Previous issue date: 2013 / Resumo: A polimerização via radical livre controlada, também conhecida como "Living Free Radical Polymerization" (LFRP) tem recebido cada vez mais atenção como uma técnica para produção de polímeros com cadeias monodispersas. Em particular, distribuições de massas moleculares estreitas são obtidas, com polidispersidade muito próxima de um. Rotas convencionais para polimerizações como esta têm sido as iônicas, no entanto, elas são extremamente sensíveis a impurezas e tipo de solvente. Desta forma, processos de polimerização via radical livre, que são muito mais versáteis e robustos a impurezas, para a produção de polímeros com estruturas controladas via processo "controlado", tem se tornado uma importante alternativa. Neste projeto de pesquisa, foi feito um estudo em nível experimental para investigar a polimerização controlada mediada por nitróxidos (NMRP, do inglês, Nitroxide Mediate Radical Polymerization), utilizando-se a polimerização em emulsão. Esse tipo de polimerização apresenta alta versatilidade industrial e também um ganho ambiental, já que um solvente orgânico é, nesse caso, substituído por água. Um dos desafios enfrentados em processar a polimerização NMRP em emulsão foi à manutenção da água em seu estado líquido, já que o processo NMRP, utilizando-se TEMPO (2, 2, 6,6-tetrametil-1-piperidinoxil) como controlador, somente se dá a uma temperatura maior que 100ºC, o que exigiu a pressurização do sistema. As quantidades de surfactante (SDS) foram alteradas de forma sistemática: 5,00 7,50 e 10,00 g. Percebeu-se que, usando 5,00g de SDS, menores polidispersidades e massas moleculares foram alcançadas, o que prova uma relação entre esses parâmetros e o número de partículas nucleadas. A relação monômero/água (v/v) também foi alterada, a saber: 0,33, 0,55, 0,70 e 0,75. Percebeu-se que a relação 0,75 forneceu as menores polidispersidades e as maiores massas moleculares. Um estudo teórico realizado com o Software Gaussian 3.0 mostrou os valores da entalpia para a espécie alquociamina dormente e para a reação global / Abstract: Controlled radicalar polymerization, known also by Living Free Radical Polymerization, has received every time more attention as being a technique for production of polymer with highly controlled microstructure. Particularly, narrow molecular weight distributions are reached, with polydispersity very close to one. Conventional routes for polymerizations like this has been the ionic, however, it is extremely sensitive to impurities and kind of solvent. This way, processes of polymerization via free radical, which are much more versatile and robust to impurities for the polymer production with controlled structures via "controlled process", has been an important alternative. In this work Nitroxide Mediated Radical Polymerization (NMRP) using TEMPO (2,2,6,6-tetrametyl-1-piperidinoxyl) as controller and emulsion polymerization was investigated. Conventional emulsion polymerization presents high industrial versatility, due to range of monomers that can be applied, and also an environmentally advantage, because an organic solvent is replaced by water. One of the challenges faced was keeping the water in liquid physical state, because the maximum efficiency of the process occurs at a temperature higher than 115ºC, what demanded the pressurization of the system. The quantities of surfactant (SDS) were systematically changed: 5.00, 7.50 and 10.00 g, respectively. It was perceived that using 5.00 g of SDS, lower values of polydispersity and molecular weight were obtained, what ensures a relation between such parameters and the number of nucleated particles. The relation monomer/water (v/v) was also changed, namely: 0.33, 0.55, 0.70 and 0.75. It was noticed that the relation 0.75 provided the lowest polydispersities and the highest molecular weights. The theoretical study performed with the Software Gaussian 3.0 showed the enthalpy values for the dormant alkoxyamine specie and for the global reaction / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

The primary objective of this research was to develop a new and efficient pathway for well-defined multicomponent homo/co/terpolymers of cyclic esters/ethers using an organocatalytic approach with an emphasis on the macromolecular engineering aspects of the overall synthesis. Macromolecular engineering (as discussed in the first chapter) of homo/copolymers refers to the specific tailoring of these materials for achieving an easy and reproducible synthesis that results in precise molecular characteristics, i.e. molecular weight and polydispersity, as well as specific structure and end?group choices. Precise control of these molecular characteristics will provide access to new materials that can be used for pre-targeted purposes such as biomedical applications. Among the most commonly used engineering materials are polyesters (biocompatible and biodegradable) and polyethers (biocompatible), either as homopolymers or when or copolymers with linear structures. The ability to create non-linear structures, for example stars, will open new horizons in the applications of these important polymeric materials. The second part of this thesis describes the synthesis of aliphatic polyesters, particularly polycaprolactone and polylactide, using a metal-free initiator/catalyst system. A phosphazene base (t?BuP2) was used as the catalyst for the ring-opening copolymerization of ?-aprolactone (??CL) and L,Lactide (LLA) at room temperature with a variety of protic initiators in different solvents. These studies provided important information for the design of a metal-free route toward the synthesis of polyester?based (bio) materials. The third part of the thesis describes a novel route for the one?pot synthesis of polyether-b polyester block copolymers with either a linear or a specific macromolecular architecture. Poly (styrene oxide)?b?poly(caprolactone)?b?poly(L,lactide) was prepared using this method with the goal of synthesizing poly(styrene oxide)-based materials since this styrene oxide (SO) monomer has been less investigated than other well-known epoxide monomers. The new one?pot synthesis of polyether?b?polyester block copolymers allowed a high degree of control with respect to the molecular weight and molecular weight distribution. It also eliminates the need for a multi-step process in which the first block must be isolated and purified prior to its subsequent use as a macroinitiator for the second block. It is also worth noting that this approach is based primarily on the use of organocatalyst because this class of block copolymers has greater potential in biomedical and pharmaceutical applications and because organocatalysts are believed to be less toxic than their metallic counterparts. The fourth part of the thesis describes the extension of the scope of the newly developed catalyst?switching approach in the synthesis of different macromolecular architectures, with a special focus on styrene oxide as a monomer, which had not previously been explored either as a linear copolymer with other monomers (except with EO) or with a macromolecular architecture such as block star or mikto arm star. The results detailed in Chapter 4 demonstrate the validity of extending the newly developed strategy to the synthesis of a variety of polymers with different macromolecular architectures. Since organic catalysts (phoshazene bases) have been utilized in this work for the synthesis of polyethers and polyesters with the aim of alleviating the toxic properties associated with metal-based catalysts, it was necessary to investigate the toxicity of this class of organocatalyst since, until now, no evidence has appeared of any attempt to address this issue. The objective of the work presented in the fifth part of this thesis was therefore to assess whether this class of organocatalysts are safe with respect to human health and whether their structure and concentration are dependent on an evaluation of the level of cytotoxicity or on other parameters. Both the pure catalyst and the polymers synthesized using this class of catalysts were tested using a CKK?8 assay, which is a very well?known protocol for measuring cytotoxicity.

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This research aims to add to the current knowledge available for miniemulsion polymerization reactions and to use this knowledge to synthesize multifunctional nanosized latex particles that have the potential to be used in catalysis. The physical properties of the latex can be adjusted to suit various environments due to the multiple functional groups present. For this research, styrene, pentafluorostyrene, azidomethyl styrene, pentafluorostyrene with azidomethyl styrene and pentafluorostyrene with styrene latexes were produced, and analyzed by dynamic light scattering. The latexes were synthesized using a miniemulsion polymerization technique found through this research. Potassium oleate and potassium 1,1,2,2,3,3,4,4-nonafluorobutane-1-sulfonate were used as surfactants during the miniemulsion polymerization reaction to synthesize pentafluorostyrene with azidomethyl styrene latex. Transmission electron microscopy data and dynamic light scattering data have been collected to analyze the structure of this latex, and it has been synthesized using a number of conditions, differing in reaction time, surfactant amount and sonication methods. We have also improved the solubility of the latex through a copper(I) catalyzed 1,3-dipolar azide-alkyne reaction, by clicking (polyethylene glycol)5000 onto the azide functional groups.

published_or_final_version / Business Administration / Master / Master of Business Administration

No description available.

Abstract This research focuses on the performance of a full-scale biotrickling filter (BTF) for treating a vented gas from an ABS (acrylonitrile-butadiene-styrene) resin plant. The BTF was constructed by reinforced concrete with a size of 5 m in width, 9 m in length, and 3.5 m in height. It consists of six individual chambers with packing materials of 4.6m in length and 4.2m in width for each. The vented gas contains styrene (SM) and acrylonitrile (AN) as two major components and has an average flow rate of 43,000 m3/h (720 m3/min) and a temperature range of 40-53¢J. Three test protocols have been studied to understand the effects of changing scrubbing method, types of packing materials, and amounts of packing materials on the pollutant removal efficacy. Two different instruments (portable FID and laboratory GC) were used to measure the VOC concentrations for both the inlet and outlet of the BTF. Many parameters were monitored for trend analysis, including gas flow rate, empty-bed gas retention time, system temperature, inlet and outlet VOC concentrations, VOC mass flow rate, organic loading, VOC removal efficiency, recirculation water volume, VOC concentration in the recirculation water, and mass flow rate of the recirculation water. These data were analyzed for discussing the technical feasibility of using BTF as an air pollution control unit for petrochemical industry. Experimental results showed that the third protocol using PVC packing materials (installed with 4.6m in length, 4.2 in width, and 0.6m in height for each of the 6 chambers) was the best setup for the target VOC removal. Without adding any special seed and supplementary nutrient, effluent of the wastewater treatment unit of the plant was introduced into the BTF as the recirculation water (pH 7-8.5, volumetric flow rate 15-30 m3/h, and temperature was 35-50¢J). A range of VOC removal efficiencies of 8.6-41% (equivalent to volumetric elimination rates of K = 41-949 g/m3.h) was obtained with loadings of L = 469-3015 g/m3.h based on the GC data. The elimination rates were 41-949 and 27.4-562 g/m3.h, respectively, for AN and SM corresponding to loadings of 121-1104 and 818-1756 g/m3.h for the two components. An average removal efficiency (K/L) of 24.5% was obtained for AN and SM regardless of the magnitude of the loading. Distribution of VOC removal was 13% by biofilms and the rest by the recirculation water. Microbiological tests revealed that Nematods was the most dominating species at high loadings and Trachelophyllum sp. was the most dominating species at lower loadings. It was also estimated that a total operating cost of NT$ 23,920/day is required and that is equivalent to a cost of NT$ 34.1 for eliminating 1 kg of VOCs from the waste gas. The data showed that the VOC loading (469-3015 g/m3.h, average 1808 g/m3.h) to the BTF was much higher than the normal design value of 30-60g/m3.h. It is suggested that a pre-treatment unit should be added into the system to lower the organic loading before the waste stream enters the BTF. In addition, the makeup recirculation water should be increased to foster the bacteria growth and to improve the absorption of VOCs from the waste gas.