L'objectif principale [i.e. principal] de ce travail était de proposer un matériau acoustique absorbant issu de recyclage et/ou recyclé pouvant être une alternative à la laine minérale encore très largement utilisée. Ce projet découlait initialement d'un besoin du Ministère des Transports du Québec (MTQ) qui souhaitait concevoir de nouveaux écrans acoustiques routiers selon les principes du développement durable définis par le gouvernement du Québec [1]. En d'autres termes, ce matériau devait être fait de matériaux recyclés et/ou recyclables, sa fabrication et sa récupération peu énergivores et ses distances de transports faibles; sous-entendant une fabrication locale [2]. Ainsi, dans cette étude nous avons clairement mis en évidence que les fibres de nylon recyclées, largement disponible [i.e. disponibles] au Québec, sont tout aussi efficaces voire supérieure [i.e. supérieures] à la traditionnelle laine minérale dont la fabrication est très énergivore et est difficilement recyclable [3-4]. Enfin un modèle simple prédictif basé sur la masse volumique de panneaux de fibres compactées a été proposé, validé et discuté.

A kaolinite-nylon 6 composite was prepared by a polycondensation reaction from 6-aminohexanoic acid (AHA) intercalated in the kaolinite interlayer space. The basal spacing of kaolinite-AHA was 1.47 nm and the basal spacing of the heated products decreased to 1.16 nm. The signals attributed to nylon 6 were detected in the 13C CP/MAS NMR spectra of the heated products. Formation of nylon 6 in kaolinite was confirmed by appearance of IR band due to amide I and amide II. Sarcosine was intercalated in kaolinite for the first time by guest displacement with methanol from the kaolinite-methanol precursor. The basal spacing of kaolinite-sarcosine was 1.27 nm. This intercalation compound was characterized by NMR, TGA, XRD, and IR. The physical and chemical properties of natural clay sample from Mirandela formation (Portugal) were determined in terms of external skin treatment. The low CEC 4,45meq/100g is consistent with high content of kaolinite in the sample

Made available in DSpace on 2014-06-12T15:52:45Z (GMT). No. of bitstreams: 2 arquivo5049_1.pdf: 474256 bytes, checksum: 37317599cafeb878be1bf92f59e6079d (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / Lipase comercial de Mucor miehei foi imobilizada em diferentes suportes, nylon, nylon-álcool polivinílico (nylon-PVA) e partículas de polisiloxano-álcool polivinílico magnetizadas (POS-PVA) e testados em relação à atividade hidrolítica. O sistema imobilizado que apresentou maior estabilidade operacional, no caso, lipase-POS-PVA foi caracterizado em relação aos parâmetros Km e Vmax aparentes, temperatura ótima e pH ótimo, usando ρ- nitrofenil palmitato como substrato. A lipase imobilizada em POS-PVA apresentou um Km aparente de 228,3μM e Vmax aparente de 36,06μmol.min-1 por miligrama de proteína, a 30oC e pH 8,0. A temperatura ótima e o pH ótimo foram respectivamente 45oC e pH = 8,0. Houve uma retenção de 69,1% de atividade após a imobilização, que permitiu o uso da enzima por um total de sete ensaios. Lipase-POS-PVA também foi empregada na síntese de ésteres. Os efeitos da razão molar ácido/álcool, da concentração de enzima imobilizada, do tamanho da cadeia carbônica dos reagentes e da estrutura do álcool sobre a formação de produto foram determinados. A síntese de butirato de butila foi maximizada para substratos contendo ácido orgânico em excesso e uma concentração de biocatalisador de 25mg/mL. A seletividade do biocatalisador em relação ao tamanho da cadeia carbônica foi diferente considerando ácidos orgânicos e álcoois. A maior concentração de produto foi obtida com ácidos orgânicos com oito e dez carbonos, enquanto que o aumento no tamanho da cadeia carbônica do álcool, de quatro para oito carbonos, provocou uma redução na síntese. O maior rendimento foi determinado para a síntese de caprilato de butila (12 carbonos). A síntese também foi influenciada pela estrutura do álcool, com a atividade máxima ocorrendo para álcool primário

A kaolinite-nylon 6 composite was prepared by a polycondensation reaction from 6-aminohexanoic acid (AHA) intercalated in the kaolinite interlayer space. The basal spacing of kaolinite-AHA was 1.47 nm and the basal spacing of the heated products decreased to 1.16 nm. The signals attributed to nylon 6 were detected in the 13C CP/MAS NMR spectra of the heated products. Formation of nylon 6 in kaolinite was confirmed by appearance of IR band due to amide I and amide II. Sarcosine was intercalated in kaolinite for the first time by guest displacement with methanol from the kaolinite-methanol precursor. The basal spacing of kaolinite-sarcosine was 1.27 nm. This intercalation compound was characterized by NMR, TGA, XRD, and IR. The physical and chemical properties of natural clay sample from Mirandela formation (Portugal) were determined in terms of external skin treatment. The low CEC 4,45meq/100g is consistent with high content of kaolinite in the sample

This research explores various immobilized enzyme support materials, including the novel nylon-6 fiber membrane (NFM), observing the increase of surface area and what effect that has on enzyme binding potential. This study also manipulates incubation and reaction conditions and observes what affect that has on activity and stability of β-galactosidase comparing various solid support materials and free enzyme. Nylon-6 fiber membranes were created using the process of electrospinning and were compared with other materials as solid support materials for enzyme binding. The other materials included polyvinylidene fluoride 5 kD nanofiltration dairy membranes, nylon-6 pellets, silica glass beads, and free—dissolved—enzyme. Scanning electron microscopy images exposed the nylon-6 fiber membrane’s large amount of surface area which coordinated with greater enzyme activity as compared to the relatively flatter surfaces of the other solid support materials. Enzyme activity was measured spectrophotometrically with the color-changing substrate ortho-Nitrophenyl-β-galactoside. NFM had greater maximum enzyme binding potential than the other solid supports. Across pH conditions ranging from 3.5 to 6.0., enzyme activity was maintained on the membrane immobilized samples whereas free enzyme did not maintain activity. Altering storage temperature (4, 22, and 50 °C) affected enzyme stability, the ability of the enzyme to maintain activity over time, of free and polyvinylidene fluoride membrane samples. However, nylon-6 fiber membrane samples maintained stability across the varying storage temperatures. Increasing the immobilization solution enzyme concentration above maximum enzyme binding capacity had no significant effect on enzyme stability for membrane immobilized samples. Although, both had lower mean stability than free enzyme by approximately 74% percent. With further development, β-galactosidase immobilized on nylon-6 fiber membranes, or other membranes, could be used in continuous processing in the dairy industry for a combination of filtration and lactose hydrolysis—creating products reduced in lactose and increased in sweetness with no “added sugars” requirement for a nutrition label and no enzyme listed as final product ingredient.

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This dissertation concerns the development of simulation and optimization technology for industrial, hydrolytic nylon-6 polymerizations. The significance of this work is that it is a comprehensive and fundamental analysis of nearly all of the pertinent aspects of simulation. It steps through all of the major steps for developing process models, including simulation of the reaction kinetics, phase equilibrium, physical properties, and mass-transfer- limited devolatization. Using this work, we can build accurate models for all major processing equipment involved in nylon-6 production. Contributions in this dissertation are of two types. Type one concerns the formalization of existing knowledge of nylon-6 polymerization mixtures, mainly for documentation and teaching purposes. Type two, on the other hand, concerns original research contributions. Formalizations of existing knowledge include reaction kinetics and physical properties. Original research contributions include models for phase equilibrium, diffusivities of water and caprolactam, and devolatization in vacuum-finishing reactors. We have designed all of the models herein to be fundamental, yet accessible to the practicing engineer. All of the analysis was done using commercial software packages offered by Aspen Technology, Cambridge, MA. We chose these packages for two reasons: (1) These packages enable one to quickly build fundamental steady-state and dynamic models of polymer trains; and (2) These packages are the only ones commercially available for simulating polymer trains. / Ph. D.

Changes in nylon 6.6 and polyester filament yarns were determined after heat treatment with dry heat at various temperatures under constant length conditions. An attempt was made to relate structural changes and changes in physical properties due to heat setting. Density, obtained by the density gradient column technique, was used to calculate the degree of crystallinity as a structural parameter. Filament tensile strength and elongation at break were measured on a constant-rate-of-extension machine, and then toughness of the sample was obtained from the load elongation curve. The amount of dye uptake was estimated spectrophotometrically. Degree of crystallinity increased significantly as temperature increased for both nylon 6.6 and polyester fibers. Tenacity decreased substantially for nylon 6.6 and increased marginally for polyester. Elongation and toughness at break decreased for both nylon 6.6 and polyester. Tenacity of nylon 6.6 decreased despite an increase in degree of crystallinity. This suggests degradation of the fibers. Therefore, degree of crystallinity appeared to be of little importance as a contributor to change in tensile strength for degraded nylon 6.6. Tenacity of polyester was well predicted by degree of crystallinity. As crystallinity increased, tenacity of polyester increased. Elongation and toughness of both nylon 6.6 and polyester decreased as degree of crystallinity increased, but the relationship to crystallinity for polyester was not significant. Dyeability of both nylon 6.6 and polyester was well predicted by degree of crystallinity. In both cases, the amount of dye uptake decreased as crystallinity increased. This research suggests that determinations for structural changes such as degradation and orientation might be utilized in addition to crystallinity to predict tenacity of nylon 6.6 and elongation and toughness of polyester. / Ph. D.