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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.
101

Synthesis, characterization, thermomechanical and rheological properties of long chain branched metallocene polyolefins /

Kolodka, Edward B. January 2003 (has links)
Thesis (Ph.D.) -- McMaster University, 2003. / Includes bibliographical references (p. 154-172). Also available via World Wide Web.
102

In situ composites of compatibilized polypropylene/liquid crystalline polymer blends /

O'Donnell, Hugh J., January 1993 (has links)
Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references. Also available via the Internet.
103

Development of commercial, sustainable processes for dyeing generic, unmodified polypropylene fiber

Gupta, Murari Lal. January 2008 (has links)
Thesis (Ph.D)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Cook, Fred; Committee Member: Beckham, Haskell; Committee Member: Bottomley, Lawrence; Committee Member: Carr, Wallace; Committee Member: Etters, Nolan. Part of the SMARTech Electronic Thesis and Dissertation Collection.
104

The mathematical modelling and experimental verification of propylene polymerization in the liquid slurry phase

Taylor, Tad William. January 1983 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1983. / Typescript. Vita. Description based on print version record. Includes bibliographical references.
105

Relationship between morphology, crystallization behavior and mechanical properties of polypropylene micro- and nanocomposites /

Zhang, Yan. January 2004 (has links)
Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references. Also available in electronic version.
106

Study of sisal fiber-reinforced polypropylene, polyethylene and polypropylene/polyethylene blend composites prepared by compression molding

Tam, Mei San. January 2005 (has links) (PDF)
Thesis (M.Sc.)--City University of Hong Kong, 2005. / At head of title: City University of Hong Kong, Department of Physics and Materials Science, Master of Science in materials engineering & nanotechnology dissertation. Title from title screen (viewed on Sept. 4, 2006) Includes bibliographical references.
107

Produção e caracterização física e mecânica de compósito plástico-madeira /

Viola, Natália Martin. January 2012 (has links)
Orientador: Rosane Aparecida Gomes Battistelle / Coorientador: Ivaldo de Domênico Valarelli / Banca: Tomas Queiroz Ferreira Barata / Banca: Adilson Renófio / Resumo: O objetivo deste estudo foi produzir plástico-madeira (wpc) com farinha de madeira e o polímero de polipropileno reciclado, e a confecção de corpos de prova por meio do processo de injeção, para realizar as análises laboratoriais. O estudo resultou em quatro formulações para o compósito, sendo a matriz polimérica, no caso o polipropileno reciclado com adição de 10%, 20% e 30% de farinha de madeira composta pela mistura do Pinus taeda e Pinus eliotti, mais uma composição com 100% polipropileno recilado. A avaliação do compósito plástico-madeira foi realizada através de ensaios dos corpos de prova injetados. Os resultados dos ensaios mostraram a possibilidade de utilização da farinha de madeira para a produção de compósitos plástico-madeira, já que esta apresenta uma granulometria fina e, considerando que há pouco consumo para o material, são muitas vezes descartados na natureza. Também foi possível a utilização do polipropileno recilado, constituído assim, em mais uma vantagem de utilização dos resíduos de plástico que poluem solo, rios e mares. O fato de não ter usado compatibilizante, é outra vantagem do estudo, pois este material apresenta forte influência no custo de produção, podendo inviabilizar o concieto da utilização de resíduos na sua composição. As composições de compósito com 30% de farinha de madeira mostraram o menor desvio padrão das composições, além de um resultado satisfatório no ensaio de impacto com 34,94 J/m. Porém, o aumento no percentual de madeira pode diminuir a resistência à tração nos compósitos, pois, mesmo que a fibra de madeira in natura apresente em média um módulo de 30GPa, o compósito depende da resistência de um agregado formado de fibras e outros elementos celulares, sofrendo influência da dispersão das fibras na matriz polimérica e da adesão entre as fases / Abstract: The aim of this study was to produce wood-plastic composites (wpc) with wood flour and polypropylene recycled polymer, and the making of specimens through the injection process, to perform the laboratory analyzes. The study resulted in four formulations for the composite, and the polymeric matrix, if recycled polypropylene with the addition of 10%, 20% and 30% of wood flour composed by mixing Pinus taeda and Pinus elliotii, over a composition with 100% recycled polypropylene. The evaluation of wood-plastic composite was performed by testing the speciments injected. The test results showed the possibility of using wood flour for the production of wood-plastic composite, since it has a fine grain size, and considering that there is little material to consumption, are often disposed in nature. It was also possible to use recycled polypropylene and, thus, a further advantage in the use of plastic waste that pollutes the soil, rivers and seas. The fact of not having used compatibilizer, is another advantage of the study, because this material has a strong influence on the cost of production and may derail the concept of using waste in its composition. The compositions of the composite with 30% wood flour showed the lowest standard deviation of the compositions, and a satisfactory result in the impact test with 34.94J/m. However, the increase in the percentage of wood can reduce the tensile strength in composities, because even if the wood fiber present in fresh medium one module 30GPa, the composite depends on the strength of an aggregate formed of fibers and other cellular elements, being influenced by fiber dispersion in the polymer matrix and the adhesivon between the phases / Mestre
108

Influência das variáveis de processo na formação e propriedades de nanocompósitos polipropileno/bentonita.

ANDRADE, Daniela de Lourdes Anjos Coutinho Simões. 12 September 2018 (has links)
Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-09-12T12:56:27Z No. of bitstreams: 1 DANIELA DE LOURDES ANJOS COUTINHO SIMÕES ANDRADE - TESE (PPGEP) 2009.pdf: 2248344 bytes, checksum: 28a93ae4236853f59fe35037c2ab6f28 (MD5) / Made available in DSpace on 2018-09-12T12:56:27Z (GMT). No. of bitstreams: 1 DANIELA DE LOURDES ANJOS COUTINHO SIMÕES ANDRADE - TESE (PPGEP) 2009.pdf: 2248344 bytes, checksum: 28a93ae4236853f59fe35037c2ab6f28 (MD5) Previous issue date: 2009 / A proposta deste trabalho foi preparar nanocompósitos de polipropileno/compatibilizante/bentonita, pelo método de intercalação na fusão, utilizando como carga uma argila sódica comercial Argel, fornecida por uma indústria local, purificada e modificada organicamente com um sal quaternário de amônio empregando diferentes métodos de preparação. Ao longo do trabalho foram utilizadas duas matrizes e dois tipos de compatibilizantes: PP H103, PP H401, Polipropileno modificado com anidrido maleico (PP-g-MA) e Copolímero de etileno e álcool vinílico (EVOH), respectivamente. As argilas foram caracterizadas por difração de raios-X (DRX), espectroscopia de infravermelho (FTIR) e análise termogravimétrica (TG) visando determinar o método de preparação mais eficiente para obtenção das argilas organofílicas. Uma vez determinado o melhor procedimento para organofilização, na segunda parte deste estudo, avaliou-se o efeito do tipo e teor de argila organofílica, bem como o tipo e teor de compatibilizante nas propriedades de filmes de polipropileno. De acordo com os resultados preliminares deste estudo, há uma indicação de que os filmes de nanocompósitos PP/PP-g-MA/argila organofílica, contendo 1% de argila organofílica e 15% de polipropileno modificado com anidrido maléico (PP-g-MA) podem ser promissores para o mercado de embalagens e poderão em um futuro próximo serem usados como um novo produto por empresas nacionais. / The purpose of this work is to prepare nanocomposites of polypropylene/compatibilizer/bentonite, by melting intercalation, with a commercial sodium clay – Argel – as filler. This clay was organically purified and modified by different methods, with a quaternary ammonium salt. The clays were characterized by X-Ray diffraction (XRD), infrared spectroscopy (FTIR) and thermogravimetric analyses (TG) to determine the most efficient preparation method. Before that, in the second stage of this study, the influence of the type and contend of organoclay in the properties of the polypropylene films was measured; the same was done for the compatibilizer. The preliminary results indicate that the nanocomposites film with 1% of organoclay and 15% of polypropylene grafted with maleic anhydride show promise as packing materials and may be used, in the near future, as a new product by the national industry.
109

Produção e caracterização física e mecânica de compósito plástico-madeira

Viola, Natália Martin [UNESP] 14 December 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-14Bitstream added on 2014-06-13T18:29:54Z : No. of bitstreams: 1 viola_nm_me_bauru.pdf: 2644948 bytes, checksum: dea71ff5b009fb7148941f2660a86dd6 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste estudo foi produzir plástico-madeira (wpc) com farinha de madeira e o polímero de polipropileno reciclado, e a confecção de corpos de prova por meio do processo de injeção, para realizar as análises laboratoriais. O estudo resultou em quatro formulações para o compósito, sendo a matriz polimérica, no caso o polipropileno reciclado com adição de 10%, 20% e 30% de farinha de madeira composta pela mistura do Pinus taeda e Pinus eliotti, mais uma composição com 100% polipropileno recilado. A avaliação do compósito plástico-madeira foi realizada através de ensaios dos corpos de prova injetados. Os resultados dos ensaios mostraram a possibilidade de utilização da farinha de madeira para a produção de compósitos plástico-madeira, já que esta apresenta uma granulometria fina e, considerando que há pouco consumo para o material, são muitas vezes descartados na natureza. Também foi possível a utilização do polipropileno recilado, constituído assim, em mais uma vantagem de utilização dos resíduos de plástico que poluem solo, rios e mares. O fato de não ter usado compatibilizante, é outra vantagem do estudo, pois este material apresenta forte influência no custo de produção, podendo inviabilizar o concieto da utilização de resíduos na sua composição. As composições de compósito com 30% de farinha de madeira mostraram o menor desvio padrão das composições, além de um resultado satisfatório no ensaio de impacto com 34,94 J/m. Porém, o aumento no percentual de madeira pode diminuir a resistência à tração nos compósitos, pois, mesmo que a fibra de madeira in natura apresente em média um módulo de 30GPa, o compósito depende da resistência de um agregado formado de fibras e outros elementos celulares, sofrendo influência da dispersão das fibras na matriz polimérica e da adesão entre as fases / The aim of this study was to produce wood-plastic composites (wpc) with wood flour and polypropylene recycled polymer, and the making of specimens through the injection process, to perform the laboratory analyzes. The study resulted in four formulations for the composite, and the polymeric matrix, if recycled polypropylene with the addition of 10%, 20% and 30% of wood flour composed by mixing Pinus taeda and Pinus elliotii, over a composition with 100% recycled polypropylene. The evaluation of wood-plastic composite was performed by testing the speciments injected. The test results showed the possibility of using wood flour for the production of wood-plastic composite, since it has a fine grain size, and considering that there is little material to consumption, are often disposed in nature. It was also possible to use recycled polypropylene and, thus, a further advantage in the use of plastic waste that pollutes the soil, rivers and seas. The fact of not having used compatibilizer, is another advantage of the study, because this material has a strong influence on the cost of production and may derail the concept of using waste in its composition. The compositions of the composite with 30% wood flour showed the lowest standard deviation of the compositions, and a satisfactory result in the impact test with 34.94J/m. However, the increase in the percentage of wood can reduce the tensile strength in composities, because even if the wood fiber present in fresh medium one module 30GPa, the composite depends on the strength of an aggregate formed of fibers and other cellular elements, being influenced by fiber dispersion in the polymer matrix and the adhesivon between the phases
110

Polypropylene and the Future of the Bassoon

January 2017 (has links)
abstract: The dearth of young bassoonists in America can be felt at every level of expertise, whether it be at professional levels where there are fewer qualified bassoonists compared to other woodwinds, or in local communities where interested pupils cannot find a teacher to guide them. In order to alleviate this scarcity, we must solve the problem at its root: young bassoonists. There have been many attempts to provide better instructional material for beginner-level bassoonists and to produce better reeds to entice more students to study the bassoon and to sustain their playing beyond the first few years. These attempts, however, fail to address another critical issue: the cost and availability of the bassoon itself. Most bassoonists in America begin their journey in public school; however, many school music programs cannot afford to purchase bassoons due to their cost. To combat this obstacle, Fox Products produced their first bassoon made of polypropylene—a synthetic material—in 1961 at a relatively low price point. This is an innovation that no other bassoon manufacturer has accomplished. An analysis of sales numbers from major instrument suppliers indicate that these bassoons have been very successful. Their availability has allowed schools to purchase instruments to educate more young bassoonists and, as a result, participant numbers of students in Texas (where public music programs are known for their strength) competing at regional and state competitions have increased over the past fifty years. Fox, through their focus on affordable student bassoons, is revitalizing young students’ interest in playing the bassoon and thus is a major factor in the reversal of the decline of bassoonists in America. / Dissertation/Thesis / Doctoral Dissertation Music 2017

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