Cette recherche s’inscrit dans un contexte d’amélioration des performances et du confort des vêtements textiles d’intervention contre le feu et la chaleur. L’objectif est de réduire le poids total des équipements de protection individuelle (EPI), en remplaçant leur structure actuelle par un tissu complexe de type « Spacer Fabric », qui résulte de l’assemblage de deux couches, aux propriétés différentes, par un fil de liage. Ces travaux de thèse se concentrent sur le développement du fil de liage et peuvent se définir comme une étude de faisabilité visant à prouver la possibilité de filer des monofilaments de « gros » diamètre (200 – 300 μm) à partir d’une solution de polyamide-imide Kermel®. Pour mener ce projet à terme, un dispositif expérimental de filage par coagulation a été développé. Entièrement automatisé, il permet aussi bien l’étude de l’influence des paramètres de filage sur la qualité des monofilaments obtenus, que la simulation d’une production de type industriel. Pour répondre à notre problématique, cet outil de prototypage a été appliqué au développement des monofilaments souhaités. Un plan d’expériences a été construit, comprenant quatre facteurs : le diamètre d’extrusion, la concentration en solvant du bain de coagulation et les taux d’étirage appliqués dans le bain et dans l’air. Cette étude expérimentale a mis en évidence l’importance de la maîtrise de la cinétique de coagulation, avec une influence hautement significative des facteurs diamètre d’extrusion et concentration du bain de coagulation, notamment sur l’évolution du taux de vide des monofilaments obtenus. / This research aims to improve the performance and the comfort requirements of textile protective clothing against heat and flames. The main purpose is to reduce the weight of such personal equipment by replacing their current structure with complex woven “Spacer Fabric”, composed of an assembly of two textile layers, having different properties, and linked by a binder yarn. These works particularly focus on the development of this binder yarn and consist in a feasibility study to demonstrate the possibility to demonstrate the possibility to spun monofilaments having a large diameter (200 – 300 μm) from a polyamide-imide solution (Kermel®). A dedicated experimental wet-spinning device has been designed to carry out this project. Such fully automated machine enables to conduct detailed studies concerning the influence of multiple spinning parameters on the physical properties of the manufactured monofilaments, therefore providing a simulation of an industrial production of such fibers. Hence, this prototyping tool has been used to develop monofilaments addressing the initially stated issue. A four factor Design of Experiments has been built to investigate the effects and combinations between the following parameters: extrusion diameter, concentration of the coagulation bath, drawing rates applied in the bath and in the air. The derived results mainly showed the importance of controlling the coagulation kinetic. Moreover, highly significant influences of both extrusion diameter and concentration of coagulation bath factors have been highlighted, especially concerning the evolution of the void fraction of the monofilaments.

京都大学 / 新制・論文博士 / 博士(工学) / 乙第13408号 / 論工博第4194号 / 新制||工||1762(附属図書館) / (主査)教授 安部 武志, 教授 作花 哲夫, 教授 阿部 竜 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DGAM

Two new bis(perfluoroalkyl)arylsulfonyl imide monomers, which contain the aryl diazonium moiety and intramolecular zwitterionic fragment, have been designed and prepared for the first time from perfluoro(3-oxa-4-pentene)sulfonyl fluoride. As promising monomer candidates for high-performance proton exchange membrane fuel cell electrolytes, these two monomers have furnished perfluorinated electrolytes that include the polymers from perfluorinated sulfonic acid or perfluorinated sulfonimide monomers. The synthesis strategies and NMR analysis are summarized and discussed in details.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第20451号 / 農博第2236号 / 新制||農||1051(附属図書館) / 学位論文||H29||N5072(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 小川 順, 教授 三上 文三, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The vast majority of commercial gas separation membrane systems are polymeric because of processing feasibility and cost. However, polymeric membranes designed for gas separations have been known to have a trade-off between permeability and selectivity as shown in Robeson's upper bound curves. The search for membrane materials that transcend Robeson's upper bound has been the critical issue in research focused on membranes for gas separation in the past decade. To that end, many researchers have explored the idea of mixed matrix membranes (MMMs). These membranes combine a polymer matrix with inorganic molecular sieves such as zeolites. The ideal filler material in MMMs should have excellent properties as a gas adsorbent or a molecular sieve, good dispersion properties in the polymer matrix of submicron thickness, and should form high quality interfaces with the polymer matrix. In order to increase gas permeance and selectivity of polymeric membranes by fabricating MMMs, we have fabricated mixed matrix membranes using carbon nanotubes (CNTs) and nano-sized mesoporous silica. Mixed matrix membranes containing randomly oriented CNTs showed that addition of nanotubes to a polymer matrix could improve its selectivity properties as well as permeability by increasing diffusivity. Overall increases in permeance and diffusivity for all tested gases suggested that carbon nanotubes can provide high diffusivity tunnels in the CNT within the polymer matrix. This result agreed well with molecular simulation estimations. In order to prepare ordered CNTs membranes, we have developed a simple, fast, commercially attractive, and scalable orientation method. The oriented CNT membrane sample showed higher permeability by one order of magnitude than the value predicted by a Knudsen model. This CNT membrane showed higher selectivities for CO₂ over other gas molecules because of preferential interaction of CO₂ with the amine functionalized nanotubes, demonstrating practical applications in gas separations. Recently, mesoporous molecular sieves have been used in MMMs to enhance permeability or selectivity. However, due to their micrometer scale in particle size, the composite membrane was extremely brittle and tended to crack at higher silica loading. In this study, we have developed fabrication techniques to prepare MMMs containing mesoporous MCM-41 nanoparticles on the order of ~50 nm in size. This smaller nanoparticle lead to higher polymer/particle interfacial area and provides opportunity to synthesize higher loading of molecular sieves in polymer matrix up to ~80 vol%. At 80 vol% of nano-sized MCM-41 silica loading, the permeability of the membrane increased dramatically by 300 %. Despite these increases in permeability, the separation factor of the MMMs changed only slightly. Therefore, these nanoscale molecular sieves are more suitable for commercialization of MMMs with very thin selective layers than are micro-sized zeolites or molecular sieves. / Ph. D.

Ce travail de thèse a consisté à améliorer certaines propriétés de revêtements fonctionnels à base de polychlorure de vinyle (PVC) plastifié et de polyamide-imide (PAI) par incorporation de nanocharges inorganiques préformées, lamellaires ou divisées. La compatibilisation des nanocharges avec la matrice dans laquelle elles ont été incorporées s’est avérée indispensable pour obtenir des films nanocomposites avec une distribution homogène et un état de dispersion le plus fin possible. Différentes stratégies de compatibilisation ont été étudiées, comme la physisorption, la chimisorption, l’intercalation ou encore la chélation d’agents compatibilisants judicieusement choisis et adaptés à chacun des systèmes. Les nouvelles nanocharges ainsi modifiées ont été caractérisées en vue de leur introduction dans la matrice. Les films nanocomposites « compatibilisés » ont été élaborés en voie solvant et/ou par polymérisation in-situ, suivie d’une gélification physique pour le PVC ou d’une réticulation chimique pour le PAI. La caractérisation morphologique des films, réalisée par DRX et MEB/MET, ainsi que les propriétés thermiques et thermomécaniques des films, évaluées par ATG, DSC et DMA, mettent en évidence l’importance de deux paramètres : la chimie de surface des nanocharges, à l’origine des interactions interfaciales nanocharge/polymère, et le procédé d’élaboration du nanocomposite. / This study aims at improving some properties of functional PVC- and PAI- based coatings by adding preformed inorganic lamellar or spherical nanofillers. The compatibilization of nanofiller with the polymer matrix in which they are introduced, is required in order to obtain nanocomposite films with an homogeneous distribution and a dispersion state as fine as possible. Different compatibilization strategies, well-suited for each system, have been studied: compatibilizer physisorption, chemisorption, intercalation or chelation. The new modified nanofillers have been characterized before their introduction into the matrix. Various strategies have been considered to obtain the “compatibilized” nanocomposite films such as the solution mixing and/or the in-situ polymerization, followed by a physical gelation or curing step for PVC- or PAI-based nanocomposites, respectively. The morphological characterization of the films, through XRD and SEM/TEM analysis, and the thermal and thermomecanical properties, evaluated by TGA, DSC and DMA, underlined the importance of two parameters: the nanofiller surface chemistry, responsible for the nanofiller/polymer interfacial interactions, and the elaboration process of the nanocomposite.

Organic semiconductors are widely studied as potential active components for consumer electronics due largely to their easily tuned properties and the promise of lower-cost solution-based processing technology. Imide-functionalized organic small molecule compounds have been one of the more important and studied organic semiconductors. However, very few imide-functionalized conjugated polymers have been reported in the literature. The body of this dissertation focuses on the synthesis, structure-property and device studies of imide-functionalized conjugated polymers. Reasons for choosing arylene imides as polymer building blocks include: a) they impart low-lying LUMOs to polymers, allowing band-gap engineering through choice of comonomers with variable electron-donating ability; b) imide-nitrogens provide points to attach side chains to manipulate solubility and solid-state packing; c) they are easily prepared. Structure-property studies include electrochemical measurements, UV-Vis absorption spectroscopy, differential scanning calorimetry (DSC), x-ray diffraction, and in some cases evaluation as active components in field-effect transistors (OFETs) and photovoltaic devices (PVDs). The published method to synthesize 3,6-dibromo-pyromellitic bisimides (PMBI) was streamlined and poly(phenylene ethynylene)s (PPEs) with variable band gaps were prepared from them (Chapter 2). As noted in all the chapters, electrochemical and optical measurements reveal that the LUMO of the polymers is indeed dictated by the arylene imide, while the HOMO, and therefore the optical energy gap is controlled through varying the electron donor monomer. Intramolecular hydrogen bonding was employed for increasing backbone coplanarity and therefore the polymer could have higher conjugation. One of these polymers demonstrated the narrowest band gap (1.50 eV) for any published PPE. Chapter 3 describes the first published conjugated copolymers from naphthalene bisimides (NBI), here using thiophene-based comonomers as donor units. Polymers with high molecular weight and decent solubility were obtained by choosing appropriate side chains. The optical energy gaps could be tuned across the visible and into the near IR. Preliminary OFET studies revealed electron mobility as high as ~0.01 cm2/Vs. One low band gap polymer provided OFETs with electron mobility of ~0.04 cm2/Vs and hole mobility of ~0.003 cm2/Vs, which is also among the highest mobilities of ambipolar polymeric semiconductors. Using the same approach as in Chapter 3, phthalimide-based monomers were incorporated into polymer backbones for developing new high performance p-type polymer semiconductors for OFETs and PVDs (Chapter 4). Some analogues based on benzothiadiazole, PMBI, and thiophene imides as acceptors were prepared for comparison. Again, high molecular weight, soluble polymers with band gaps spanning the visible and into the near IR were obtained. OFETs from one of the polymers yielded hole mobility ~0.3 cm2/Vs under ambient atmosphere without post-processing thermal annealing, which places it squarely within the state-of-the-art for conjugated polymers. Due to the high mobility and low band gap, this polymer also leads to PVDs with moderately good power conversion efficiency (PCE: ~2%).

Commercially available 4,4′-dichlorodiphenylsulfone (DCDPS) was successfully disulfonated with fuming sulfuric acid to yield 3,3′-disodiumsulfonyl-4,4′-dichlorodiphenylsulfone (SDCDPS). Subsequently, DCDPS and SDCDPS were systematically reacted with 4,4′-biphenol under nucleophilic step polymerization conditions to generate a series of high molecular weight, film-forming, ductile, ion conducting copolymers. These were converted to the acid form and investigated as proton exchange membranes for fuel cells. Hydrophilicity increased with the level of sulfonation. However, water sorption increased gradually until about 50 mole percent SDCDPS was incorporated, and thereafter showed a large increase to yield water soluble materials for the 100% SDCDPS system. Atomic force microscopy (AFM) confirmed that the morphology of the copolymers displayed continuity of the hydrophilic phase at 60 mole percent SDCDPS. Conductivity measurements in the 40-50 mole percent SDCDPS range, where excellent mechanical strength was maintained, produced values of 0.1 S/cm or higher which were comparable to the control, Nafion™. These compositions also show a high degree of compatibility with heteropolyacids such as phosphotungstic acid. These inorganic compounds provide a promising mechanism for obtaining conductivity at temperatures well above the boiling point of water and membrane compositions containing them are being actively pursued. The water soluble 100% SDCDPS system was further investigated by successfully functionalizing the endgroups to afford aromatic amines via appropriate endcapping with m-aminophenol. Oligomers and polymers from 5-30 kg/mole number average molecular weight were synthesized and well characterized by NMR spectroscopy, endgroup titrations and size exclusion chromatography. The diamino-telechelic sulfonated segment was reacted with several dianhydrides and diamines to produce multiblock, hydrophobic polyimide-hydrophilic sulfonated polyarylene ether copolymers. Both ester-acid and amic acid synthesis routes were utilized in combination with spin-casting and bulk imidization. A series of tough, film-forming segmented copolymers was prepared and characterized. AFM measurements demonstrated the generation of quite well defined, nanophase-separated morphologies which were dependent upon composition as well as aging in a humid environment. Characterizations of the segmented copolymers for conductivity, and water and methanol sorption were performed and comparisons to state-of-the-art perfluorinated Nafion™ systems were made. It is concluded that the segmented or block systems have the potential to enhance certain desirable PEM characteristics in fuel cells, particularly those related to swelling, retention of mechanical strength at elevated temperatures, and critical adhesion issues in membrane electrode assemblies. / Ph. D.

Natural and synthetic polymers are highly related to people's daily life in every perspective and determine everyone's life quality. This study investigated the interactions between polymer thin films and other molecules, specifically natural polymer films with other components in plant and fungal cell walls, crosslinked thermoplastic films with solvent molecules, as well as commodity thermoplastic films with air and moisture during aging by a powerful surface analysis instrument, a quartz crystal microbalance with dissipation monitoring (QCM-D). The assembly and interactions of glucan and chitin are crucial for understanding the fungal infection mechanism. Adsorption of mixed-linkage glucan (MLG) onto regenerated chitin (RChitin) and cellulose (RC) surfaces were investigated by QCM-D and atomic force microscopy (AFM). MLG was irreversibly adsorbed onto both surfaces and formed soft hydrogel-like layers with viscoelastic properties. This work established a QCM-D method to mimic the assembly of natural polymers in fungal cell walls and provided insight into the interactions of these polymers with chitin and cellulose. Poly(ether imide) (PEI) has poor solvent resistance towards solvents including chloroform, dimethylformamide (DMF), dichloromethane (DCM), and N-methyl pyrrolidone (NMP). Exposure to these solvents severely affects the thermal and mechanical performances of PEI. Therefore, crosslinked PEI (X-PEI) films was prepared from azide-terminated PEI (N₃-PEI-N₃) via a thermal crosslinking reaction. X-PEIs maintain outstanding solvent resistance towards common solvents by swelling ratio tests using QCM-D. Meanwhile, the thermal and mechanical properties of X-PEI were enhanced compared to the original PEI. Photo-oxidation is one of the dominant degradation mechanisms affecting the lifespan of polymers. The effect of photooxidative aging on the physiochemical properties of low-density polyethylene (LDPE) films were investigated using QCM-D, differential scanning calorimetry (DSC), and tensile stress-strain tests. The crystallinity, mechanical properties, and weight loss were correlated to understand the aging behavior. Materials after aging showed higher tensile stress and modulus, with reduced mass and elongation properties. Particularly, the aging-induced damage of polymer chain integrity was first determined by QCM-D through the evolution of mass loss during aging, providing supports to the changes of mechanical properties under aging. / Doctor of Philosophy / Natural polymers and thermoplastics are two major materials that are highly related to modern life. The interactions of these polymers with other molecules are important research topics for people to understand and predict the material properties. This dissertation studied the following three topics using a quartz crystal microbalance with dissipation monitoring (QCM-D): 1) interactions between plant natural polymer films and polymers in fungal cell wall; 2) solvent resistance of crosslinked thermoplastic films; and 3) physiochemical changes during photo-oxidation degradation of thermoplastic films. Pathogenic fungal cells can attack beneficial plant cell hosts by adhering themselves onto the plant cells, followed by penetration and enzymatic degradation of the multilayered plant cell walls until the host is digested. Therefore, the interaction between the components in fungal and plant cell walls is critical to understand pathogenic fungal cell invasion. Adsorption of mixed-linkage glucan (MLG) onto regenerated chitin (RChitin) and cellulose (RC) surfaces was monitored by QCM-D and atomic force microscopy (AFM). An irreversible binding interaction of MLG with chitin and cellulose films and a soft hydrogel-like layer on both surfaces were observed in our work. Poly(ether imide) (PEI) is a high-performance polymer with excellent thermal and mechanical properties. However, the good solubilities in common organic solvents that facilitate reasonable processibility limits its applications in solvent-related domains. Several methods of PEI crosslinking were developed in the literature to improve solvent resistance. This study prepared crosslinked PEI (X-PEI) films from azide-terminated PEI (N₃-PEI-N₃) via a simple thermal crosslinking reaction. X-PEI had better resistance to organic solvents from QCM-D measurements and maintained good thermal and mechanical performances. Photo-oxidation from air and sunlight slowly degrades plastics, shortens their service time, and leads to environmental pollution. This work bridged the gap between molecular integrity and its effect on the overall macroscopic mechanical changes through accurate measurement of the mass loss during degradation using a QCM-D. This work is essential in ensuring polymer design and active environmental protection.

A busca por membranas com propriedades adequadas a separação de gases em escala industrial tem levado a modificação e sIntese de polImeros de engenharia, com objetivo de obter membranas com propriedades adequadas. Uma das modificaçoes que tem se apresentado promissora é a inserção de grupos sulfônicos em polImeros comerciais. Espera-se que o polImero sulfonado apresente um aumento na permeação de gases polares, em relação a gases apolares, devido a sua estrutura mais polar e flexIvel. Neste contexto, o objetivo do presente trabalho é a sIntese e caracterização de membranas de poli(éter imida) sulfonada para a permeação de gases. Um planejamento experimental foi desenvolvido, em diferentes condiçoes reacionais de temperatura, tempo e excesso de um dos reagentes (ácido acético), para a sIntese de poli(éter imida) sulfonada (SPEI). Através deste planejamento, constatou-se que as variáveis que mais influenciam o grau de sulfonação são a temperatura e o tempo. O polImero com o maior grau de sulfonação, determinado por capacidade de troca iônica (IEC= 92 mEq H+/g), foi utilizado para o preparo da membrana de SPEI, obtida pela técnica de inversão de fase por evaporação do solvente, utilizando-se clorofórmio como solvente. Este filme foi caracterizado a partir das seguintes análises: espectroscopia de infravermelho (FTIR), calorimetria diferencial de varredura (DSC), análise termogravimétrica (TGA) e microscopia eletrônica de varredura (MEV), a fim de avaliar a influência da inserção do grupo sulfônico na matriz polimérica. O espectro de infravermelho de SPEI apresentou bandas relacionadas as vibraçoes assimétricas em 1240 cm-1 (ligação O=S=O), ligação simétrica em 1171 cm-1 (O=S=O) e ligação S-O entre 1010-1024 cm-1. Isto indica a presença de grupos sulfônicos. A análise de DSC foi realizada entre 150-250C. Nesta faixa, não foram observadas alteraçoes na temperatura de transição vItrea (Tg) do polImero modificado (217C). Acredita-se que a decomposição do grupo sulfona aconteça antes da temperatura atingir o Tg do polImero. Esta suposição é confirmada na análise de TGA. As imagens de MEV mostraram que foram obtidos filmes livres de poros e defeitos. A membrana da SPEI foi utilizada no ensaio de permeaçao dos gases 02, N2 e C02, a fim de determinar a permeabilidade e seletividade da membrana. As permeabilidades encontradas para o gas oxigênio foram de 0,76 barrer para a PEI e 0,46 barrer para a SPEI. A seletividade do dióxido de carbono em relaçao ao oxigênio aumentou de 3,5, na membrana de PEI, para 4,83, na membrana de SPEI. Em relaçao ao nitrogênio, as permeabilidades medidas foram 0,064 barrer e 0,043 barrer, para a PEI e para a SPEI, respectivamente, enquanto a seletividade em relaçao ao C02 aumentou de 41,1 para 55,5. Estes resultados indicam que o efeito de sorçao predominou devido ao aumento das interaçöes moleculares, reduzindo assim o volume livre, o que tornou a membrana sulfonada mais compacta, com permeabilidade menor e maior seletividade. Estes resultados corroboram com a premissa de que a sulfonaçao é um processo promissor para o desenvolvimento de membranas mais eficientes. / The search for membranes with suitable properties for gas separation in industrial scale has led to the modification and synthesis of engineering polymers with the purpose of obtaining membranes with superior properties. 0ne of the modifications that have been considered promising is the insertion of sulfonic groups in commercial polymers. Due to its structure more polar and flexible, it is expected that the sulfonated polymer present an increase in polar gas permeation in relation to nonpolar gases. In this context, the objective of this work is the synthesis and characterization of membranes of poly (ether imide) sulfonated for the permeation of gases. An experimental design was developed in different reaction conditions of temperature, time and an excess of one of the reagents (acetic acid), for the synthesis of poly (ether imide) sulfonated, SPEI. Through this planning, it was found that the variables that most influenced the degree of sulfonation are temperature and time. The polymer with the highest degree of sulfonation, by ion exchange capacity (IEC = 92 mEq H+ I g), was used to prepare SPEI membrane obtained by the technique of solvent evaporation, using chloroform. This film was characterized from the following analysis: infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to evaluate the influence of insertion of the sulfonic group in the polymer matrix. The infrared spectrum showed bands of SPEI related to asymmetric vibrations at 1240cm- 1 (S = 0 = 0), in symmetric stretch at 1171 cm-1 (0 = S = 0) and S0 stretch between 1010-1024cm-1. This indicates the presence of sulfonic groups. The DSC analysis was carried out between 150-250C. In this range, there are no significant changes in glass transition temperature of the modified polymer (217C). It is believed that the decomposition of the sulfone group occurs before the temperature reaches the Tg of the polymer. This assumption is confirmed in the TGA analysis. The images of SEM showed that films were obtained free of pores and defects. The membrane SPEI obtained by the technique of solvent evaporation, was used for testing permeation of gases 02, N2 and C02 in order to determine the permeability and selectivity of the membrane. The permeabilities found for oxygen were 0.76 barrer for PEI and 0.46 barrer for SPEI. The selectivity of carbon dioxide relative to oxygen increased from 3.5 to 4.83. Regarding nitrogen, the permeability measurements were 0.064 barrer and 0.043 barrer for the PEI and the SPEI, respectively, while the selectivity relative to C02 increased from 41.1 to 55.5. These results indicate that the predominant effect of sorption due to increased molecular interactions, thus reducing the free volume, made the membrane sulfonated more compact with lower permeability and higher selectivity. These results agree with the premise that the sulfonation is a promising process for the development of more efficient membranes.