Orientador: João Sinezio de Carvalho Campos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T13:40:00Z (GMT). No. of bitstreams: 1 Giordano_JoaoBatista_D.pdf: 4390680 bytes, checksum: 205aa7153da8e4745f9366e58adcb8cf (MD5) Previous issue date: 2007 / Resumo: Dentre as técnicas de modificação de superfícies aplicadas na indústria para melhorar adesão, o tratamento por descarga corona é amplamente utilizado. Durante o tratamento por descarga coro na, espécies ativas são geradas, as quais podem reagir com a superfície do polímero ocasionando quebra de cadeias e formação de radicais, criando assim grupos polares na superfície e conseqüentemente, aumentando a sua energia superficial e propriedade de adesão. Neste trabalho utilizaram-se tecidos de poliéster e de algodão. Nos processos convencionais de preparação de tecidos são usados agentes químicos que agridem os efluentes têxteis, assim a descarga corona propõe-se como tratamento prévio do material sem ação de tais agentes, sendo tratamento único e apenas físico. Os objetivos deste trabalho são: 1. Tratar com descarga corona tecidos de poliéster e tecidos de algodão (engomado, lavado e desengomado); 2. Verificar hidrofilidade e absorção de corantes em tecidos de algodão tratados com descarga corona; 3. Verificar propriedades mecânicas em tecidos tratados com descarga corona. 4. Verificar a adesão de pigmentos em de tecidos de poliéster tratados com corona. Tecidos foram submetidos à descarga: corona variando-se o tempo exposição e altura entre os eletrodos, em seguida foi realizada testes de hídrofilidade, absorção de corante tipo reativo, adesão de pigmentos, solidez a lavagem e ensaios de resistência à tração e alongamento. Foi utilizada a técnica de microscopia óptica, ensaio de hidrofilidade para caracterizar os efeitos causados. Os resultados mostram que: houve aumento da hidrofilidade do tecido de algodão que de 50% em amostra sem tratamento passou até a 280% com o tratamento, observou-se também que com te~pos de 1 mino já ocorrem modificações nos tecidos quanto a hidrofilidade e absorção de corantes; houve aumento da absorção de corante nas regiões tratadas principalmente em processos contínuos de tingimento; ocorreu boa aderência de pigmentos em tecidos de poliéster tratados; não ocorrem alteração das propriedades mecânicas (resistência a tração e alongamento) nas amostras tratadas. / Abstract: Amongst the techniques of modification of surfaces applied in the industry to improve adhesion, the treatment for discharge corona widely is used. During the treatment for discharge corona, active species are generated, which can consequently react with the surface of polymer causing chain in addition and formation of radicals, thus creating polar groups in the surface and, increasing its superficial energy and property of adhesion. In this work they had been used weaveed of polyester and cotton. In the conventional processes of fabric preparation they are used chemical agents whom the effluent textile attack, thus the discharge corona is considered as previous treatment of the material without action of such agents, being treatment only e only physicist. The objectives of this work are: 1.To deal with discharge corona weaveed to polyester and fabrics cotton (starchy, washed and dissolved the gum); 2. To verify water absorption and absorption of corantes in fabrics of cotton treated with discharge corona; to 3.Verificar mechanical properties in fabrics dealt with discharge corona. 4. To verify the pigment adhesion in of treated polyester fabrics with corona. Fabrics had been submitted to the discharge corona varying the time exposition and height between the electrodes and, after that water absorption tests had been carried through, absorption of corante reactive type, pigment adhesion, solidity the laudering and assays of tensile strenght and allonge. The technique of optic microscopy was used, assay of water absorption to characterize the caused effect. The results show that: it had increase of the hidrofilidade of the cotton fabric that of 50% in sample without treatment passed until 280% with the treatment, was 9.lso observed that with times of 1 min. already the water absorption and absorption of corantes occur modifications in fabrics how much; it had increase of the absorption of corante in the regions treated mainly in continuous processes of dyeing good pigment tack occurred in treat polyester fabrics; they do not occur alteration of the mechanical properties (resistance the traction and allonge) in the treated samples. / Doutorado / Ciencia e Tecnologia de Materiais / Doutor em Engenharia Química

O presente estudo tem como objetivo desenvolver e avaliar métodos de confecção de mantas híbridas de fibras curtas de vidro e sisal visando as necessidades da indústria automotiva na produção de componentes com menor custo e menor massa específica. Neste trabalho foram moldados por compressão compósitos de resina poliéster reforçados por mantas (25% em volume) de fibra de vidro/sisal, híbridas e isoladas. Foram desenvolvidos quatro métodos de confecção de mantas: Manual (disposição manual de fibras), Água (disposição de fibras em fase aquosa), Leito-ar (arranjo de fibras via leito fluidizado) e Vibracional (deposição de fibras em meio vibracional). De modo a comparar condições foram utilizados mais dois métodos variantes: Manual-lav (deposição manual de fibras fibra de vidro lavada) e Etanol (deposição de fibras em fase etílica). O trabalho foi dividido em rotas de ensaios onde inicialmente utilizou-se apenas a fibra de sisal de modo a obter comprimento e tratamento ideais para esta fibra. Nas demais rotas variou-se o teor de fibra de vidro incorporada (0, 25, 50, 75 e 100% e seu complemento em sisal) até a escolha de uma composição. Os compósitos produzidos pelos diferentes métodos foram avaliados através de análises de propriedades físicas (massa específica, absorção de umidade e teor de vazios) e propriedades mecânicas (resistência à tração, módulo de elasticidade e resistência ao impacto). A morfologia dos compósitos foi analisada via SEM (microscopia eletrônica de varredura). Os resultados indicaram o tratamento de água destilada para as fibras de sisal e um comprimento ideal de fibra de 3 cm. Mostraram também que a água destilada e o etanol afetam a superfície da fibra de vidro podendo remover partículas e substâncias. Compósitos com teor de 50% de fibra de vidro demonstraram propriedades mecânicas superiores as dos compósitos reforçados apenas com sisal puro, porém com menor custo e massa específica que os compósitos contendo 100% de fibra de vidro. A análise dos diferentes métodos demonstrou que os métodos Manual e Leito-ar produziram compósitos com melhores propriedades mecânicas. Contudo, método Leito-ar é o mais indicado para futuras aplicações industriais. / This work is focused at development and evaluation of confection methods of short fibers hybrid mants aiming attend the necessities of automobile industry in the production of small parts with smaller cost and specific weight. Were developed different methods in the confection of hybrids mants from short fibers: manual deposition of the fibers, watery phase deposition of the fibers, fibers arrangement by stream bed fluidized and deposition of the fibers by vibrational method. The analysis of the methods was provided by evaluation of the processed composites. The first part of the work consisted in the appraising of hybrid composites with 0, 25, 50, 75 e 100% of fiber glass and the remained in sisal. The analysis of the results showed, for 50% content, higher mechanical properties comparing to the composites reforced only with sisal, however with lower cost and specific weight than composites with 100% of fiber glass. The composites maded by different methods were estimated in relation to physical properties (specific weight, water absorption and void content) and mechanical properties (tensile strength, elasticity modulus and impact resistance). The morfology of the composites was analyzed by SEM (scanning electronic microscopy). The results showed that the 3 cm length is ideal for the procedure utilizated. The sisal fibers washed in distilled water had shown, in general, superior performance than fibers in natura or chemically treated. It was noted that the increasing of fiber glass in the hybrids composites results in the strengthening of the mechanical properties of the composites, however the sisal increment in the composition reduced the specific weight of the final product. The analysis of the diferent methods showed that the manual deposition of the fibers and fibers arrangement by stream bed fluidized were the methods that manufactured composites with the best mechanical properties. The method of deposition by stream bed fluidized can be applied in the confecction of hybrids mants with short fibers for different types of naturals and synthetic fibers and your implementation is easy and of low cost using the compressed air installation existing in industry.

L’objectif de cette étude est de synthétiser et de caractériser des polyesters entre le diméthylcétène et des composés carbonylés choisis (acétone, méthyléthylcétone et acéthaldéhyde) par deux voies distinctes : une copolymérisation directe, et une voie passant d’abord par la synthèse de la beta-lactone puis sa polymérisation par ouverture de cycle. La caractérisation a mis en évidence la structure parfaitement alternée du polyester entre le diméthylcétène et l’acétone, et des structures plus complexes avec la méthyléthylcétone et l’acétaldéhyde. Les analyses ont également montré le caractère polymorphe complexe de ces copolymères. Les trois beta-lactones correspondantes ont également été synthétisées. Seule la polymérisation de la beta-lactone avec l’acétaldéhyde a été menée à bien, du fait de son faible encombrement stérique. Enfin, une étude cinétique par infrarouge a également été effectuée et a permis de mieux connaître les cinétiques de polymérisation par ouverture de cycle. / The aim of this study is to synthesise and to characterise polyesters between dimethylketene and chosen carbonyled compounds (acetone, methylethylketone and acetaldehyde) by two distinct pathways: a direct copolymerisation, and another path proceeding in the synthesis of the beta-lactone then its ring opening polymerisation. The characterisation has highlighted the perfectly alternated structure of the polyester between dimethylketene and acetone, and more complex structures with dimethylketone and acetaldehyde. The analyses have also shown the complex polymorphism of these copolymers. The three corresponding beta-lactones have been synthesised. Only the polymerisation of the acetaldehyde beta-lactone has been accomplished because of its weak steric hindrance. At last, an infrared kinetic study has also been carried out and has permitted a better comprehension of the kinetic of the ring opening polymerisation.

Controlling conformation of macromolecules, both in solution and solid state, has remained an exciting challenge till date as it confronts the entropy driven random coil conformation. Folded forms of biomacromolecules, like proteins and nucleic acids, have served as role-models to the scientists in terms of designing synthetic foldamers. The folded functional forms of proteins and nucleic acids have been shown to rely heavily on various factors, like directional hydrogen bonding, intrinsic conformational preferences of the backbone, solvation (e.g. hydrophobic effects), coulombic interactions, charge-transfer interactions, metal-ion complexation, etc. Chapter-1 discusses various designs of synthetic polymers explored by research groups world-over to emulate the exquisite conformational control exercised by biomacromolecular systems. Our laboratory has been extensively involved since 2004 in designing charge-transfer complexation induced folding of flexible donor-acceptor (DA) polymeric systems, such as those shown in Scheme 1. It was observed that such polymers adopt a folded conformation in polar solvents, like methanol, in the presence of an excess of an appropriate alkali metal ion. To explore folding in the solid state, Jonas and co-workers recently showed that a polyethylene-like polyester with long alkylene segments containing periodically located pendant propyl group forms a semicrystalline morphology with alternating crystalline and amorphous regions primarily because of the periodic folding of the backbone due to the steric exclusion of the propyl branches from the crystalline domains. In order to explore immiscibility-driven folding of polyethylene-like polyesters, Roy et al. designed a periodically grafted amphiphilic copolymer (PGAC) containing long alkylene segments (mimicking polyethylene) and pendant oligoethyleneglycol chains at periodic intervals (Scheme 2). Scheme 2: Proposed folding of a periodically grafted amphiphilic copolymer It was demonstrated that immiscibility between the hydrocarbon backbone and pendant PEG segments drives the polymer to adopt a folded zigzag conformation as shown in Scheme 2. The above synthetic strategy, however, does not permit easy structural variation of the side chain segments because the side-chain segment is covalently linked to the malonate monomer. In Chapter-2, a more general strategy to prepare periodically grafted copolymers has been described. In an effort to do so, we designed a series of clickable polyesters carrying propargyl/allyl functionality at regular intervals along the polymer backbone, as shown in Scheme 3. Scheme 3: Periodically clickable polyesters for the preparation of periodically grafted copolymers The polyesters were prepared by reacting either 2-propargyl-1,3-propanediol, 2,2-dipropargyl-1,3-propanediol or 2-allyl-2-propargyl-1,3-propanediol with an alkylene diacid chloride, namely 1,20-eicosanedioic acid chloride, under solution polycondensation conditions. Since these polyesters carry either, one propargyl, two propargyls or one propargyl and one allyl group on every repeat unit, it provides us an opportunity to synthesise exact graft copolymers with one side chain, two side chains or even two dissimilar side chains per repeat unit. In Chapter-3, the periodically clickable polyesters were reacted with MPEG-350 (PEG 350 monomethyl ether) azides using Cu(I) catalyzed azide-yne click reaction to generate periodically grafted amphiphilic copolymers (PGAC) carrying crystallizable hydrophobic backbone and pendant hydrophilic MPEG-350 side-chains (Scheme 4). Since the PGACs carry either one or two pendant MPEG-350 chains on every repeat unit, it allowed us to examine the effect of steric crowding on the crystallization propensity of the central alkylene segment. Scheme 4: Functionalization of periodically clickable polyesters with MPEG 350 azide by azide-yne click reaction From DSC studies, it was observed that increase in steric crowding at junctions resulting from increased side-chain volume hinders effective packing of the hydrocarbon backbone. As a result, both transition temperatures and the enthalpies associated with these transitions decreases. SAXS and AFM studies revealed the formation of lamellar morphology with alternate domains of PEG and hydrocarbon. Based on these observations, we proposed that self-segregation between hydrophobic backbone and hydrophilic side-chains induce the backbone to adopt a folded zigzag conformation (Scheme 5). Scheme 5: Schematic depiction of self-segregation induced folding of PGAC and their assembly on mica surface (AFM image) In order to study the effect of solvent polarity on conformational evolution of the periodically grafted amphiphilic copolymers, we randomly incorporated pyrene in the backbone of the polymer by reacting a small fraction (~ 5 mole %) of the propargyl groups with pyrene azide. Fluorescence study of the pyrene labelled polymer showed that increase in solvent polarity increases the intensity of the excimer band dramatically; this suggests the possible collapse of the polymer chain to the folded zigzag form. In an extension of this work, the PGAC was further used as template to synthesise layered silicates that appears to replicate the lamellar periodicity seen in the polymer. In order to study the effect of reversing the amphiphilicity on self-segregation, in Chapter-4, we synthesised a series of clickable polyesters carrying PEG segments of varying lengths, namely PEG 300, PEG 600 and PEG 1000, along the polymer backbone. The polymers were prepared by trans-esterification of 2-propargyl dihexylmalonate with different PEG-diols. These polyesters were then clicked with docosyl (C22) azide using Cu(I) catalyzed azide-yne click reaction to generate the desired periodically grafted amphiphilic polymers carrying crystallizable hydrophobic pendant chains at periodic intervals; the periodicity in this case was governed by the length of the PEG diols (Scheme 6). Scheme 6: PGACs carrying hydrophilic PEG backbone and crystallizable hydrophobic pendant docosyl chains Varying the average periodicity of grafting provided an opportunity to examine its consequences on the self-segregation behavior. Given the strong tendency of the pendant docosyl segments to crystallize, DSC studies proved useful to analyse the self-segregation; DOCOPEG 300 clearly exhibited the most effective self-segregation, whereas both DOCOPEG 600 and DOCOPEG 1000 showed weaker segregation. Based on the observations from DSC studies, we proposed that the PEG backbone adopts a hairpin like conformation (Scheme 7). Scheme 7: Proposed self-segregation through hairpin like conformation of backbone PEG segments In order to confirm the bulk morphology, we carried out small angle X-ray scattering (SAXS) and atomic force microscopic (AFM) studies. The SAXS profiles confirmed the observations from DSC studies, and only DOCOPEG 300 exhibited well-defined lamellar ordering. Thus, it is clear that the length of the backbone PEG segment (volume-fraction) strongly influences the morphology of the PGACs. Based on the inter-lamellar spacing from SAXS and the height measurements from AFM studies (Scheme 8), we proposed that these polymers form lamellar morphology through inter-digitation of the pendant docosyl side-chains. The observations from Chapters 3 and 4 suggested that the crystallization of the backbone has a dramatic effect on the conformation of the polymer backbone. In order to explore the possibility of independent crystallization of both backbone and pendant side-chains, the periodically clickable polyesters, described in Chapter-2, were quantitatively reacted with a fluoroalkyl azide, namely CF3(CF2)7CH2CH2N3 using Cu(I) catalyzed azide-yne click reaction; Chapter-5 describes these polyesters carrying long chain alkylene segments along the backbone and either one or two perfluoroalkyl segments located at periodic intervals along the polymer chain (Scheme 9). DSC thermograms of two of the samples showed two distinct endotherms associated with the melting of the individual domains, while the WAXS patterns confirm the existence of two separate peaks corresponding to the inter-chain distances within the crystalline lattices of the hydrocarbon (HC) and fluorocarbon (FC) domains; this confirmed the occurrence of independent crystallization of both the backbone and side chains. Scheme 10: Left-variation of SAXS profile of all three polymers as a function of temperature, Right- molecular modelling of representative FC-HC-FC triblock structures. Interestingly, a smectic-type liquid crystalline phase was observed at temperatures between the two melting transitions. SAXS data, on the other hand, revealed the formation of an extended lamellar morphology with alternating domains of HC and FC (Scheme 10). The inter-lamellar spacing calculated from SAXS matches reasonably well with those estimated from TEM images. Based on these observations, we proposed that the FC modified polymers adopt a folded zigzag conformation whereby the backbone alkylene (HC) segment becomes colocated at the center and is flanked by the perfluoroalkyl (FC) groups on either side, as depicted in Scheme 11. Melting of alternate HC domains first leads to the formation of a smectic-type liquid crystalline mesophase, wherein the crystalline FC domains retain the smectic ordering; this was confirmed by polarizing light microscopic observations. Scheme 11: Schematic presentation of self-segregation induced folding of polymer chains; and hence crystallization assisted assembly of these singly folded chains to form lamellar structure One interesting challenge would be to create unsymmetrical folded structures, wherein the top and bottom segments of the zigzag folded form would be occupied by two different segments, such as PEG and FC, whereas the backbone alkylene segment would form the central domain; this would lead to the possible formation of consecutive domains of PEG, HC and FC through immiscibility driven self-segregation process. In Chapter-6, several approaches to access such systems have been described; one such design that could have resulted in the successful synthesis of a periodically clickable polymer carrying orthogonally clickable propargyl and allyl groups along the backbone in an alternating fashion is depicted in (Scheme 12). The parent polyester was successfully synthesized and the propargyl group was first clicked with the FC-azide to yield the FC-clicked polyester; however, several attempts to click MPEG-SH onto the allyl groups using thiol-ene click reaction failed. Scheme 12: Scheme for the synthesis of alternating orthogonally clickable polymer In order to accomplish our final objective, we chose to first prepare the FC-clicked diacid chloride and polymerize it with an azide-alkyne clickable macro-diol, as depicted in Scheme 13; this approach was successful and yielded the desired clickable polyester bearing the FC segments at every alternate location. This polymer was then clicked with PEG-750 azide to yield the final targeted polymer that carries mutually immiscible FC and PEG-750 segments at alternating positions along the polymer backbone. The occurrence of self-segregation of FC, PEG-750 and the alkylene backbone (HC) was first examined by DSC studies, which appeared to suggest the presence of three peaks, although these were not very well-resolved. Scheme 13: Schematic for the synthesis of the polymer carrying FC and PEG 750 alternatingly along the backbone A schematic depiction of the anticipated organization of such unsymmetric folded macromolecules is shown in Scheme 15; it is evident that because of mutual immiscibility, the layers will be organized such that the FC domains of adjacent layers will be together and similarly the PEG domains of adjacent layers will also be together. Such an organization would lead to an estimated spacing that would correspond to a bilayer of the folded structures. Interestingly, SAXS study (Scheme 14) reveals the formation of lamellar morphology with a d-spacing of 14.6 nm. Scheme 14: Figure 6.10: SAXS profile of the polymer PE-FC-PEG 750 In order to gain an estimate of the expected inter-lamellar spacing, the end-to-end distance of a model repeat-unit was computed to be ~ 9.4 nm. It is, therefore, evident that the inter-lamellar spacing of 14.6 nm seen in the SAXS is significantly larger and must represent a bilayer type organization (Scheme 15). In this regard it is important to say that the organization of these alternatingly functionalized folded chains should give a variety of d-spacings. Because of highest electron density contrast of FC among PEG, HC and FC, we proposed that the d-spacing calculated from the SAXS profile corresponds to ‘d4’ in Scheme 15. This first demonstration of the formation of zigzag folded unsymmetric entities bearing dissimilar segments on either side of the folded chain holds exciting potential for a variety of different applications and beckons further investigations. Scheme 15: Schematic for the proposed self-assembly of the singly folded polymer chains

Les polyesters insaturés sont des résines thermodurcissables particulièrement appréciées pour leur facilité de mise en œuvre et leur coût modéré. Cependant, comme tous les polymères organiques ils ont une réaction au feu médiocre, ce qui est critique dans un certains nombres de d'applications. L'objectif de cette thèse était d'élaborer de nouvelles formulations de résines ayant un comportement au feu amélioré. La première stratégie développée a été le greffage de monomères phosponés dans la matrice polyester. Des monomères méthacryliques et styrénique ont été synthétisés et utilisés pour remplacer une partie du styrène dans la résine. La stabilité thermique des résines modifiées est diminuée, mais leur comportement au feu est globalement meilleur. Des effets du phosphore en phase gazeuse et en phase condensée ont pu être mis en évidence.Dans une seconde partie, une sélection de particules se distinguant par leur nature, leur taille et leur facteur de forme a été testée. Si l'impact des ces charges est assez limité lorsqu'elles sont utilisées individuellement, des tests calorimétriques ont révélé que certaines combinaisons de particules pouvaient améliorer significativement la réaction au feu des résines. Enfin, des associations d'additifs phosphorés et de particules submicroniques ont été investiguées. Le polyphosphate d'ammonium se distingue des autres additifs par un impact très important sur le comportement au feu et particulièrement par le charbonnement important qu'il engendre, cependant sa combinaison avec des charges inorganiques ne s'est pas révélée probante. / Unsaturated polyesters are thermoset resins particularly appreciated for their low cost and easy processing. Nevertheless one of their main drawbacks is their poor fire resistance. The aim of this PhD thesis was to prepare new resin formulations with an improved fire behaviour. The first part of this work was dedicated to the grafting of phosphorous monomers in the polyester matrix. Methacrylic and styrenic monomers were synthesized and used to replace of part of the styrene in the resin. Resin thermal stability was decreased, but on the whole their fire behaviour was improved. Condensed phase and gas phase effects of phosphorus were highlighted.In a second part, a screening of various kinds of particles with different sizes was performed. Calorimetric tests revealed that, while the effect of these particles used alone is limited, a decrease of resin flammability could be achieved with specific combinations. Finally, commercial phosphorous additives were associated with submicronic fillers. From all the additives tested, ammonium polyphosphate stands out, with a powerful impact on the resin fire reaction and especially a much increased charring. However, its combination with inorganic particles was not conclusive.

Orientador: João Sinezio de Carvalho Campos / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T01:48:34Z (GMT). No. of bitstreams: 1 Liba_AdemirDonizeti_M.pdf: 4797015 bytes, checksum: 1351ff08893b1a29731246cf2e4cd3c8 (MD5) Previous issue date: 2004 / Resumo: A resina de poliéster insaturada (RPI) é um polímero termofixo de baixo peso molecular obtido por condensação, o processo inicia-se através da esterificação entre diálcoois e diácidos saturados e insaturados, com o aumento do peso molecular do polímero, a retirada da água, que é gerada como subproduto da reação, torna-se difícil e lança-se mão do uso do vácuo ou de um maior fluxo de gás inerte para finalização da reação. Quanto à produção em escala industrial, apesar de conhecerem-se métodos de produção contínua, esta na maioria das indústrias é conduzida em bateladas com tempo de duração em média de 20 horas, podendo variar de acordo com a escolha das matérias primas utilizadas. Para a obtenção do polímero dentro dos parâmetros especificados, se faz necessário o controle dos radicais carboxilas, medidos através do índice de acidez (IA) e do peso molecular médio numérico (Mn), sendo este último parâmetro obtido de maneira indireta através da viscosidade(n). Para a viscosidade pode-se utilizar a escala Gardner, ou o viscosímetro cone e placa. A marcha de execução destas técnicas envolve várias etapas, desde a retirada da amostra até a obtenção do resultado da medida, sendo que para a amostragem, dependendo do equipamento disponível, esta pode implicar na interrupção do processo produtivo. Neste trabalho apresenta-se uma alternativa para o controle da reação, através do infravermelho próximo (NIR), em substituição às técnicas convencionais, com a vantagem do acompanhamento e do controle ser passível de execução em tempo real e sem a necessidade da retirada de amostras. Utilizou-se como base para o trabalho, a utilização anterior do NIR em processos envolvendo outros polímeros, tais como o policloreto de vinila (PVC), o policarbonato, o poliuretano e outros. Para verificar-se a viabilidade da utilização do NIR em substituição as técnicas convencionais, os valores obtidos para o IA e a viscosidade através destas técnicas foram comparados estatisticamente aos valores obtidos pelo NIR, obtendo-se forte correlação, com confiabilidade estatística de 95%. Com os resultados obtidos concluiu-se que o NIR pode ser utilizado com vantagens para o controle do processo de obtenção da resina de poliéster insaturada / Abstract: The unsaturated polyester resin (UPR) is a thermosetting polymer of low molecular weight obtained by condensation, the process begins through a esterification, between glycols and a mix of saturated and unsaturated acids, when the molecular weight of the polymer increase, the retreat of the water, generated as by-product of the reaction, if it turns more difficult and are necessary to use a vacuum or a larger flow of inert gas for finalization of the reaction. The production in industrial scale, in spite of they know each other methods of continuous production, are made in a batch with 20 hours long, could vary in agreement with the choice of the raw materials. For the obtaining of the polymer in the specified parameters, are necessary the control of the acid number (AN) and of the molecular weight (Mn), being this last obtained parameter in an indirect way through the viscosity. For measures those properties, are used as tools for the measure of the acidity number by titrimetric methods, and for the viscosity are use the Gardner scale, or the cone and plate viscometer. These techniques involves several stages, from the take of the sample to the obtaining of the result of the measure, and for obtain the sampling, depending on the available equipment, this can implicate in the interruption of the productive process. In this work we propose an alternative for the control of the reaction, by near infrared spectrometer (NIR), in substitution to the conventional techniques, with the advantage of the attendance and of the control to be susceptible to execution in real time and without the need of take samples. It was used as base for the work, the previous work of NIR in processes involving other polymeric materials, such as polyvinyl chloride (PVC), polycarbonate, the polyurethane and others. To verify the viability of the use of NIR in substitution of the conventional techniques, the values obtained for acid number and viscosity through these techniques were compared to the values obtained by NIR, being obtained strong correlation, with statistical reliability of 95%. With the obtained results it was ended that NIR can be used with advantages for the process control of unsaturated polyester resin / Mestrado / Ciencia e Tecnologia de Materiais / Mestre em Engenharia Química

In this work, hyperbranched aromatic polyesters-polyphenols based on 4,4-bis(4’ hydroxy¬phenyl)pentanoic acid (BHPPA) were prepared and, according to the authors knowledge, for the first time tested as precursors for polyurethane bulk resins and coatings. Comparison of poly-BHPPA with competing products The materials prepared in this work show better properties than their aliphatic polyester-polyol analoga based on 2,2-bis-(hydroxymethyl)propanoic acid (BHMPA). Especially, the solubility of poly-BHPPA in organic solvents is better and poly-BHPPAs also do not tend to microphase separation during their reaction with isocyanates, in contrast to poly-BHMPAs. The poly-BHPPA and the polyurethane networks made from them display higher Tg values than analogous poly- BHMPA compounds. Because of the high Tg of the reacting and final systems, curing must occur at elevated temperatures (90°C) in order to avoid undercure. The lower reactivity of phenolic OH groups prevents the reaction from being too fast at that temperature. A drawback of the polyurethanes based on the aromatic polyesters-polyols prepared is the lower thermal stability of their urethane bonds, if compared to aliphatic urethanes. An interesting possibility for future investigations would be the modification of the BHPPA monomer in order to change the OH functionality from phenolic to aliphatic OH, e.g. by replacement of the phenolic OH by hydroxymethyl or hydroxyethyl groups (requires a strong modification of the monomer synthesis) or simpler by reacting the phenolic OH of BHPPA with a suitable reagent like oxirane, which would lead to groups like O-CH2-CH2-OH in the place of the phenolic OH. Such a BHPPA modification should in turn yield modified “poly-BHPPA” polycondensates, which would combine the advantages of poly-BHPPA with those of aliphatic OH precursors of polyurethanes. Poly-BHPPA synthesis Hyperbranched polymers of the 4,4-bis-(4’-hydroxyphenyl)pentanoic acid (BHPPA) were synthesized successfully by the catalyzed (by dibutyltin diacetate) polycondensation of BHPPA. The products obtained were oligomers with number average molecular weight ranging from 1800 to 3400 g/mol (polymerization degree of ca. 6 to 12), displaying a first moment of functionality in the range 7 to 14. Such products were good OH precursors for the preparation of polyurethane coatings, because higher functional polymers would gel at low conversions. The analysis of the functional groups (determination of acid and hydroxyl numbers) and the 1H-NMR and the 13C-NMR spectroscopy were found to be good methods for the determination of molecular weights. The polydispersity of the poly-BHPPA products was in the range 3.5 to 6. Their degree of branching was found to be in the range 0.36 to 0.47. Poly-BHPPA containing aliphatic polyols as core monomers were also prepared successfully. Difunctional and trifunctional core monomers usually reached a full conversion of their OH groups, while the tetra- and hexafunctional core monomers were converted only to 89%. In all these products however, a considerable amount, usually even a majority, of the polymer molecules were core free. The poly-BHPPA products prepared displayed relatively high glass transition temperatures, in the range of 84°C to 114°C, obviously due to interactions between the phenol groups and to hydrogen bridging. The thermal stability of these products was also high, with decomposition occurring near 350°C (at a heating rate of 10°C / min) Kinetics investigations of the poly-BHPPA reactivity towards isocyanates The poly-BHPPA are polyphenols and were expectedly found to react significantly slower with isocyanates than aliphatic alcohols. The reactivity of poly BHPPA was also found to be somewhat lower than that of the monofunctional, low molar-mass 4 ethylphenol. Hexamethylene diisocyanate trimer, Desmodur N3300, was found to be more reactive than hexamethylene diisocyanate (HDI) or butyl isocyanate in all experiments, possibly due to a substitution effect. The substitution effect can be explained by a change of microenvironment caused by conversion of isocyanate group and OH group into urethane groups. The reactions of low-molecular-mass alcohols or phenols with low molecular weight isocyanates followed well the 2nd order kinetics, while the reactions of poly-BHPPA with isocyanates show deviations from ideal 2nd order kinetics at higher conversions. All the kinetics experiments were carried out under catalysis by dibutyltin dilaurate. This catalyst inhibits the undesired reaction of isocyanate groups with moisture. It was also found that the catalysis was necessary to reach reasonable curing times for poly-BHPPA based polyurethane networks. The uncatalyzed systems reacted extremely slowly. Preparation of polyurethane networks from poly-BHPPA The poly BHPPA products prepared were used successfully as OH functional precursors of polyurethane networks. The networks prepared contained only very low sol fractions. Acetone and also ethylene diglycol dimethylether (diglyme) were found to be good swelling solvents for the networks prepared, while methyl propyl ketone was a much poorer solvent and aromatic compounds like toluene or xylene practically did not swell the poly BHPPA based polyurethanes. The networks prepared contain a relatively high amount of cyclic bonds, 40 to 50% in the finally cured state, which is an expected result for systems with precursors of high functionality and with small distances between the functional groups. The temperature of glass transition (Tg) of the networks prepared (ranging from 68°C to 126°C) depends of the poly BHPPA precursor used: it increases with increasing molecular mass and with increasing core functionality. The choice of the isocyanate crosslinker also influences Tg: the networks made from HDI show higher Tg values, than networks made from the same poly BHPPA but crosslinked with Desmodur N3300 (Tri HDI). The urethane bonds in the networks prepared start to decompose near 140°C. The easier degradation of PU with aromatic urethane bonds is a disadvantage in comparison with aliphatic polyurethanes, whose decomposition starts at 200°C. The surfaces of polyurethane coatings prepared are smooth, displaying a roughness of ca. 20-25 nm, and relatively hydrophilic: the contact angle with water was found to be near 80°. The prepared networks are also relatively hard, possessing the Shore D hardness of 70.

Die vorliegende Arbeit liefert einen Beitrag zum Verständnis der komplexen Struktur-/Eigenschaftsbeziehungen dünner Schichten hochverzweigter Polyester. Für die umfassende Charakterisierung wurde eine Vielzahl analytischer Methoden kombiniert. Des Weiteren wurde das Anwendungspotential dieser Schichten hinsichtlich möglicher Sensoranwendung anhand der Adsorption von Modellproteinen gewichtet. Dazu war es notwendig verschieden Methoden zur Stabilisierung dieser Schichten zu entwickeln.

Plant derived oils bear intrinsic double-bond functionality that can be utilized directly for the thiol–ene reaction. Although terminal unsaturations are far more reactive than internal ones, studies on the reversible addition of thiyl radicals to 1,2-disubstituted alkenes show that this is an important reaction. To investigate the thiol–ene coupling reaction involving these enes, stoichiometric mixtures of a trifunctional propionate thiol with monounsaturated fatty acid methyl esters (methyl oleate or methyl elaidate) supplemented with 2.0 wt.% Irgacure 184 were subjected to 365-nm UV-irradiation and the chemical changes monitored. Continuous (RT– FTIR) and discontinuous (NMR and FT–Raman) techniques were used to follow the progress of the reaction and reveal details of the products formed. Experimental results supported by numerical kinetic simulations of the system confirm the reaction mechanism showing a very fast cis/trans-isomerization of the alkene monomers (<1.0 min) when compared to the total disappearance of double-bonds, indicating that the rate-limiting step controlling the overall reaction is the hydrogen transfer from the thiol involved in the formation of final product. The loss of total unsaturations equals thiol consumption throughout the entire reaction; although product formation is strongly favoured directly from the trans-ene. This indicates that initial cis/trans-isomer structures affect the kinetics. High thiol–ene conversions could be easily obtained at reasonable rates without major influence of side-reactions demonstrating the suitability of this reaction for network forming purposes from 1,2-disubstituted alkenes. To further illustrate the validity of this concept in the formation of cross-linked thiol–ene films a series of globalide/caprolactone based copolyesters differing in degree of unsaturations along the backbone were photopolymerized in the melt with the same trithiol giving amorphous elastomeric materials with different thermal and viscoelastic properties. High thiol–ene conversions (>80%) were easily attained for all cases at reasonable reaction rates, while maintaining the cure behaviour and independent of functionality. Parallel chain-growth ene homopolymerization was considered negligible when compared with the main coupling route. However, the comonomer feed ratio had impact on the thermoset properties with high ene-density copolymers giving networks with higher glass transition temperature values (Tg) and a narrower distribution of cross-links than films with lower ene composition. The thiol–ene systems evaluated in this study serve as model example for the sustainable use of naturally-occurring 1,2-disubstituted alkenes at making semi-synthetic polymeric materials in high conversions with a range of properties in an environment-friendly way. / Vegetabiliska oljor som innehåller dubbelbindningar kan användas direkt för thiolene reaktioner. Trots att terminala dubbelbindningar är mycket mer reaktiva än interna visar dessa studier att den reversibla additionen av thiyl radikaler till 1,2-disubstituerade alkener är en viktig reaktion. För att undersöka tiol–ene reaktionerna, som ivolverar dessa alkener förbereddes stökiometriska blandningar av en trifunktionell propionat tiol och enkelomättade fettsyrametylestrar (metyloleat eller metyl elaidat) samt 2.0 vikt.% Irgacure 184. Dessa blandningar utsattes för 365-nm UV strålning och de kemiska förändringarna studerades. De kemiska förändringarna analyserades med olika kemiska analysmetoder; realtid RT–FTIR, NMR och FT–Raman. Dessa användes för att analysera de kemiska reaktionerna i realtid och följa bildandet av produkterna. Reaktionsmekanismen bekräftades med hjälp av experimentella data och beräkningar av numeriska och kinetiska simuleringar för systemet. Resultaten visar en mycket snabb cis/trans-isomerisering av alkenmonomeren (<1.0 min) jämfört med den totala förbrukningen av dubbelbindningarna, vilket indikerar att det hastighetsbegränsande steget kontrolleras av väteförflyttningen från tiolen till slutprodukten. Förbrukningen av den totala omättade kolkedjan är lika med tiolförbrukningen under hela reaktionen, även om bildandet av produkten gynnas från trans-enen. Detta indikerar att den första cis/trans-isomerstrukturen påverkar kinetiken. Höga tiol-ene utbyten kan enkelt erhållas relativt snabbt utan inverkan av sidoreaktioner. Detta innebär att denna reaktion kan användas som nätverksbildande reaktion för flerfunktionella 1,2-disubstituted alkenmonomerer. Vidare användes fotopolymerisation i smälta på en serie globalid/kaprolaktonbaserade sampolyestrar med varierad grad av omättnad med samma tritiol vilket resulterade i bildandet av amorfa elastomeriska material med olika termiska och viskoelastiska egenskaper. Hög omsättning (>80%) uppnåddes relativt enkelt för samtliga blandningar oberoende av den initiala funktionaliteten. Homopolymerisation av alkenen var försumbar i jämförelse med den tiol–en-reaktionen. Mängden alkengrupper har inverkan på härdplastsegenskaperna där en hög andel alken ger en nätstruktur med högre glastransitionstemperatur (Tg). Tiol–ene reaktionen utvärderades i modellsystem baserade på naturlig förekommande 1,2-disubstituterade alkener för att demonstrera konceptet med tiol-förnätade halvsyntetiska material. / QC 20110915

A chemoselective catalyst is preferred in a chemical reaction where protecting groups otherwise are needed. The two lipases Candida antarctica lipase B and Rhizomucor miehei lipase showed large chemoselectivity ratios, defined as (kcat/KM)OH / (kcat/KM)SH, in a transacylation reaction with ethyl octanoate as acyl donor and hexanol or hexanethiol as acyl acceptor (paper I). The chemoselectivity ratio of the uncatalyzed reaction was 120 in favour of the alcohol. Compared to the uncatalyzed reaction, the chemoselectivity was 730 times higher for Candida antarctica lipase B and ten times higher for Rhizomucor miehei lipase. The KM towards the thiol was more than two orders of magnitude higher than the KM towards the corresponding alcohol. This was the dominating contribution to the high chemoselectivity displayed by the two lipases. In a novel approach, Candida antarctica lipase B was used as catalyst for enzymatic synthesis of thiol-functionalized polyesters in a one-pot reaction without using protecting groups (paper II). Poly(e-caprolactone) with a free thiol at one of the ends was synthesized in an enzymatic ring-opening polymerization initiated with mercaptoethanol or terminated with either 3-mercaptopropionic acid or g-thiobutyrolactone.