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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Characterization and analysis of osteopontin-immobilized poly(2-hydroxyethyl methacrylate) /

Martin, Stephanie M., January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 198-210).
32

Morphology and mechanical properties of PMMA/CNT composites /

Bhalla, Shallu, January 1900 (has links)
Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 91-96). Also available in electronic format on the Internet.
33

Poly <subscript L>-lactic acid (PLLA) and poly methyl methacrylate (PMMA) blends and their interaction with CO2 at sub-critical conditions /

Yao, Baisheng, January 1900 (has links)
Thesis (M.SC.) - Carleton University, 2007. / Includes bibliographical references. Also available in electronic format on the Internet.
34

Reactive compatibilization of PBT/ABS blends by methyl methacrylate, glycidyl methacrylate, ethyl acrylate terpolymers /

Hale, Wesley Raymond, January 1998 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. Includes bibliographical references (leaves 255-263). Available also in a digital version from Dissertation Abstracts.
35

Trimethylsilylated allyl complexes of groups I-V formation, structure, and catalytic reactions /

White, Rosemary Elaine. January 2006 (has links)
Thesis (Ph. D. in Chemistry)--Vanderbilt University, Dec. 2006. / Title from title screen. Includes bibliographical references.
36

Correlating Gene Transfection Efficiency and the Physical Properties of Various Cationic Poly(methacrylate) Systems

Tan, J. F., Too, Heng-Phon, Hatton, T. Alan, Tam, K. C. 01 1900 (has links)
Transfection efficiencies of several polymeric gene carriers were compared and correlated quantitatively to the amounts of cellular accumulation of plasmid DNA and to the expression of mRNA by quantitative real time PCR. Three cationic methacrylate polymer systems with similar chemical structure were used in this study, namely: poly(dimethylamino)ethyl methacrylate (PDMA) homopolymer, PEO-b-PDMA copolymer and PEO-b-poly(diethylamino)ethyl methacrylate (PEO-b-PDEA) copolymer. Despite their similar chemical structures, their transfection efficiencies were significantly different. PEO-b-PDEA copolymer was significantly less efficient as gene carrier compared to both PDMA and PEO-b-PDMA systems. Results from quantitative real-time polymerase chain reaction (real-time PCR), cytotoxicity and Zeta potential measurements showed correlations between the physical properties of the polymers and the efficiencies of cellular uptake of the transgene and transfections. In the case of PEO-b-PDEA system, cytotoxicity was due primarily to the excess polymers that did not participate in the DNA binding. In addition, the inability of the polymer/DNA complexes to interact with cell effectively was identified as the main barrier for high efficiency of transfection. This study demonstrated that the use of quantitative real-time PCR in combination with other physical characterization techniques can provide greater insights into the transfection barrier at different cellular levels. / Singapore-MIT Alliance (SMA)
37

Desenvolvimento e caracterização de uma resina adesiva experimental acrescida de hidroxietil acrilamida / Development and characterization of an experimental adhesive with the addition of hydroxyethil acrylamide

Rodrigues, Stefani Becker January 2013 (has links)
O objetivo do presente estudo foi desenvolver e caracterizar resinas adesivas contendo hidroxietil acrilamida (HEAA). Três grupos de resinas adesivas foram formulados, GHEAA33% (33,3% de HEAA + 66,6% de bisfenol A glicedil dimetacrilato - BisGMA), GHEAA50% (50% de HEAA + 50% de BisGMA) e GHEMA (33,3% de hidroxietil metacrilato - HEMA + 66,6% de BisGMA). Parâmetros como resistência à flexão (n= 12), grau de inchamento (n= 3), temperatura de transição vítrea (n= 3) e degradação em solvente (n= 5) foram avaliados de cada resina adesiva. Em adição foi avaliado com calorimetria exploratória diferencial (DSC), o processo de polimerização das resinas experimentais (n= 3), bem como dos homopolímeros componentes, BisGMA, HEMA, HEAA, HEMA* sem adição de etil 4- dimetilaminobenzoato (EDAB) e HEAA* sem adição de EDAB. Os resultados foram analisados estatisticamente com auxílio de ANOVA de uma via, teste de Tukey e teste t pareado. Todas as resinas adesivas e homopolímeros, exceto HEMA, HEAA* e HEMA*, apresentaram uma alta taxa de polimerização e um alto grau de conversão. Não houve diferença estatística entre as resinas adesivas para a temperatura de transição vítrea e a degradação em solvente (p>0,05). Entretanto, o grupo GHEAA33% apresentou a menor variação de grau de inchamento (p<0,05) e os menores valores de resistência à flexão (p<0,05) quando comparado com o grupo GHEMA. Considerando que a hidroxietil acrilamida foi capaz de promover o aumento do processo de polimerização de resinas adesivas experimentais e, tendo em vista sua potencial resistência à degradação hidrolítica e ainda, com base nos resultados dos demais ensaios, o grupo GHEAA33%, parece reunir as melhores condições de desenvolvimento de resinas adesivas inovadoras. / The purpose of this study was to develop an experimental adhesive resin using hydroxyethyl acrylamide (HEAA). Three groups of experimental resin were formulated, GHEAA33% (33.3% HEAA + 66.6% Bisphenol A glycerolate dimethacrylate- BisGMA), GHEAA50% (50% HEAA + 50% BisGMA), and GHEMA (33.3% 2-Hydroxyethyl methacrylate- HEMA + 66.6% of BisGMA). Parameters such as flexural strength (n= 12), swelling degree (n= 3), glass transition temperature (n= 3), and softening in solvent (n= 5) were evaluated for each adhesive resin. In addition, the polymerization process of each adhesive resin group (n= 3), as well as for the homopolymers, BisGMA, HEMA, HEAA, HEMA* without ethyl 4-dimethylaminobenzoate (EDAB), and HEAA* without EDAB, were also evaluated using differential scanning calorimetry (DSC). The results were analyzed using one way ANOVA, Tukey’s test, and Student’s t-test. For all of the resins and homopolymers evaluated, except for homopolymers HEMA, HEMA* and HEAA* homopolymer, a high rate of polymerization and a high degree of conversion were observed. There was no significant difference (p > 0.05) for the glass transition temperature and for softening in solvent for the adhesive resins assayed. In contrast, the GHEAA33% group exhibited less swelling degree (p < 0.05) and reduced flexural strength (p < 0.05) compared to the GHEMA group. HEAA was also found to promote the polymerization process and was resistant to hydrolytic degradation. Thus, GHEAA33% appears to be a promising alternative for the production of innovative adhesive resins.
38

Desenvolvimento e caracterização de uma resina adesiva experimental acrescida de hidroxietil acrilamida / Development and characterization of an experimental adhesive with the addition of hydroxyethil acrylamide

Rodrigues, Stefani Becker January 2013 (has links)
O objetivo do presente estudo foi desenvolver e caracterizar resinas adesivas contendo hidroxietil acrilamida (HEAA). Três grupos de resinas adesivas foram formulados, GHEAA33% (33,3% de HEAA + 66,6% de bisfenol A glicedil dimetacrilato - BisGMA), GHEAA50% (50% de HEAA + 50% de BisGMA) e GHEMA (33,3% de hidroxietil metacrilato - HEMA + 66,6% de BisGMA). Parâmetros como resistência à flexão (n= 12), grau de inchamento (n= 3), temperatura de transição vítrea (n= 3) e degradação em solvente (n= 5) foram avaliados de cada resina adesiva. Em adição foi avaliado com calorimetria exploratória diferencial (DSC), o processo de polimerização das resinas experimentais (n= 3), bem como dos homopolímeros componentes, BisGMA, HEMA, HEAA, HEMA* sem adição de etil 4- dimetilaminobenzoato (EDAB) e HEAA* sem adição de EDAB. Os resultados foram analisados estatisticamente com auxílio de ANOVA de uma via, teste de Tukey e teste t pareado. Todas as resinas adesivas e homopolímeros, exceto HEMA, HEAA* e HEMA*, apresentaram uma alta taxa de polimerização e um alto grau de conversão. Não houve diferença estatística entre as resinas adesivas para a temperatura de transição vítrea e a degradação em solvente (p>0,05). Entretanto, o grupo GHEAA33% apresentou a menor variação de grau de inchamento (p<0,05) e os menores valores de resistência à flexão (p<0,05) quando comparado com o grupo GHEMA. Considerando que a hidroxietil acrilamida foi capaz de promover o aumento do processo de polimerização de resinas adesivas experimentais e, tendo em vista sua potencial resistência à degradação hidrolítica e ainda, com base nos resultados dos demais ensaios, o grupo GHEAA33%, parece reunir as melhores condições de desenvolvimento de resinas adesivas inovadoras. / The purpose of this study was to develop an experimental adhesive resin using hydroxyethyl acrylamide (HEAA). Three groups of experimental resin were formulated, GHEAA33% (33.3% HEAA + 66.6% Bisphenol A glycerolate dimethacrylate- BisGMA), GHEAA50% (50% HEAA + 50% BisGMA), and GHEMA (33.3% 2-Hydroxyethyl methacrylate- HEMA + 66.6% of BisGMA). Parameters such as flexural strength (n= 12), swelling degree (n= 3), glass transition temperature (n= 3), and softening in solvent (n= 5) were evaluated for each adhesive resin. In addition, the polymerization process of each adhesive resin group (n= 3), as well as for the homopolymers, BisGMA, HEMA, HEAA, HEMA* without ethyl 4-dimethylaminobenzoate (EDAB), and HEAA* without EDAB, were also evaluated using differential scanning calorimetry (DSC). The results were analyzed using one way ANOVA, Tukey’s test, and Student’s t-test. For all of the resins and homopolymers evaluated, except for homopolymers HEMA, HEMA* and HEAA* homopolymer, a high rate of polymerization and a high degree of conversion were observed. There was no significant difference (p > 0.05) for the glass transition temperature and for softening in solvent for the adhesive resins assayed. In contrast, the GHEAA33% group exhibited less swelling degree (p < 0.05) and reduced flexural strength (p < 0.05) compared to the GHEMA group. HEAA was also found to promote the polymerization process and was resistant to hydrolytic degradation. Thus, GHEAA33% appears to be a promising alternative for the production of innovative adhesive resins.
39

Desenvolvimento e caracterização de uma resina adesiva experimental acrescida de hidroxietil acrilamida / Development and characterization of an experimental adhesive with the addition of hydroxyethil acrylamide

Rodrigues, Stefani Becker January 2013 (has links)
O objetivo do presente estudo foi desenvolver e caracterizar resinas adesivas contendo hidroxietil acrilamida (HEAA). Três grupos de resinas adesivas foram formulados, GHEAA33% (33,3% de HEAA + 66,6% de bisfenol A glicedil dimetacrilato - BisGMA), GHEAA50% (50% de HEAA + 50% de BisGMA) e GHEMA (33,3% de hidroxietil metacrilato - HEMA + 66,6% de BisGMA). Parâmetros como resistência à flexão (n= 12), grau de inchamento (n= 3), temperatura de transição vítrea (n= 3) e degradação em solvente (n= 5) foram avaliados de cada resina adesiva. Em adição foi avaliado com calorimetria exploratória diferencial (DSC), o processo de polimerização das resinas experimentais (n= 3), bem como dos homopolímeros componentes, BisGMA, HEMA, HEAA, HEMA* sem adição de etil 4- dimetilaminobenzoato (EDAB) e HEAA* sem adição de EDAB. Os resultados foram analisados estatisticamente com auxílio de ANOVA de uma via, teste de Tukey e teste t pareado. Todas as resinas adesivas e homopolímeros, exceto HEMA, HEAA* e HEMA*, apresentaram uma alta taxa de polimerização e um alto grau de conversão. Não houve diferença estatística entre as resinas adesivas para a temperatura de transição vítrea e a degradação em solvente (p>0,05). Entretanto, o grupo GHEAA33% apresentou a menor variação de grau de inchamento (p<0,05) e os menores valores de resistência à flexão (p<0,05) quando comparado com o grupo GHEMA. Considerando que a hidroxietil acrilamida foi capaz de promover o aumento do processo de polimerização de resinas adesivas experimentais e, tendo em vista sua potencial resistência à degradação hidrolítica e ainda, com base nos resultados dos demais ensaios, o grupo GHEAA33%, parece reunir as melhores condições de desenvolvimento de resinas adesivas inovadoras. / The purpose of this study was to develop an experimental adhesive resin using hydroxyethyl acrylamide (HEAA). Three groups of experimental resin were formulated, GHEAA33% (33.3% HEAA + 66.6% Bisphenol A glycerolate dimethacrylate- BisGMA), GHEAA50% (50% HEAA + 50% BisGMA), and GHEMA (33.3% 2-Hydroxyethyl methacrylate- HEMA + 66.6% of BisGMA). Parameters such as flexural strength (n= 12), swelling degree (n= 3), glass transition temperature (n= 3), and softening in solvent (n= 5) were evaluated for each adhesive resin. In addition, the polymerization process of each adhesive resin group (n= 3), as well as for the homopolymers, BisGMA, HEMA, HEAA, HEMA* without ethyl 4-dimethylaminobenzoate (EDAB), and HEAA* without EDAB, were also evaluated using differential scanning calorimetry (DSC). The results were analyzed using one way ANOVA, Tukey’s test, and Student’s t-test. For all of the resins and homopolymers evaluated, except for homopolymers HEMA, HEMA* and HEAA* homopolymer, a high rate of polymerization and a high degree of conversion were observed. There was no significant difference (p > 0.05) for the glass transition temperature and for softening in solvent for the adhesive resins assayed. In contrast, the GHEAA33% group exhibited less swelling degree (p < 0.05) and reduced flexural strength (p < 0.05) compared to the GHEMA group. HEAA was also found to promote the polymerization process and was resistant to hydrolytic degradation. Thus, GHEAA33% appears to be a promising alternative for the production of innovative adhesive resins.
40

Copolímeros anfifílicos constituídos de metacrilato de sacarose e monômeros acrílicos / Amphiphilic copolymers consisting of sucrose methacrylate and acrylic monomers

Oliveira, Heitor Fernando Nunes de 17 August 2018 (has links)
Orientador: Maria Isabel Felisberti / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-17T19:45:22Z (GMT). No. of bitstreams: 1 Oliveira_HeitorFernandoNunesde_M.pdf: 3345603 bytes, checksum: 2f9d75a948fbe215b8da7ff775997c04 (MD5) Previous issue date: 2011 / Resumo: Neste trabalho foram sintetizados copolímeros anfifílicos constituídos de 1¿-O-metacrilato de sacarose (SMA) com os monômeros comerciais metacrilato de metila (MMA) ou N-isopropilacrilamida (NIPAAm), em diferentes composições molares. Catálise enzimática foi empregada para obtenção do monômero regioseletivamente monofuncional 1¿-O-metacrilato de sacarose, com rendimento reacional superior a 70 % de SMA. Esta etapa foi baseada em trabalho estabelecido na literatura e adequada às condições deste projeto. O SMA foi copolimerizado com os monômeros NIPAAm e MMA via polimerização radicalar. Estes materiais foram caracterizados por ressonância magnética nuclear de C (RMN C), cromatografia de permeação em gel (GPC), calorimetria diferencial de varredura (DSC) e análise termogravimétrica (TGA). Os resultados revelam o êxito da síntese de copolímeros aleatórios com elevada massa molar (ordem de 10 g mol), com propriedades físico-químicas dependentes da composição. Estes copolímeros foram submetidos a ensaios de solubilidade, intumescimento e de avaliação do comportamento de fases de soluções aquosas com a temperatura. Todos os polímeros sintetizados se apresentaram solúveis em algum solvente, evidenciando que tratam-se de macromoléculas de cadeias lineares. Para ambas as séries de copolímeros constatou-se que o caráter anfifílico é fortemente dependente da composição, tal como era esperado. Apenas o homopolímero de SMA e o copolímero de SMA e MMA mais rico no primeiro monômero são solúveis em água, enquanto que os demais copolímeros desta série intumescem neste solvente e a quantidade de água sorvida aumenta com o aumento da fração de SMA. A temperatura para separação de fases de soluções aquosas dos copolímeros constituídos de SMA e NIPAAm é superior em relação à temperatura observada para o poli(N-isopropilacrilamida), o que se atribui a maior hidrofilicidade dos copolímeros / Abstract: In this work, amphiphilic copolymers consisting of conjugated sucrose 1'-O-methacrylate (SMA) with methyl methacrylate (MMA) or N-isopropylacrylamide (NIPAAm) in different molar ratio were synthesized. Enzymatic catalysis was employed for obtaining regioselective monofunctional sucrose 1'-O-methacrylate with reaction yield above 70 % of SMA. This step was based on established work in literature and adequate conditions of this project. The SMA has been copolymerized with NIPAAm and MMA monomers by free radical polymerization. These materials were characterized by C nuclear magnetic resonance (C NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results show the successful synthesis of random copolymers with high molar mass (order of 10 g mol), with physical and chemical properties dependent on composition. Solubility, swelling tests and the phase behavior studies of aqueous solutions were also performed for these copolimers. All polymers are soluble in some solvent, showing that these are linear macromolecules. For both series of copolymers was found that the amphiphilic character depends strongly on composition, as expected. Only the homopolymer of SMA and the copolymer of SMA and MMA richer in the first monomer are soluble in water, while the rest of this series copolymers swell in this solvent and the amount of sorbed water increases with increasing SMA fraction. The temperature for phase separation of aqueous solutions of copolymers composed of NIPAAm and SMA is higher than in the observed temperature for poly(N-isopropylacrylamide), which is attributed to higher hydrophilicity of the copolymers / Mestrado / Físico-Química / Mestre em Química

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