Polyurethanes
Mostrando 25-36 de 46 artigos, teses e dissertações.
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25. Estudo da incorporação de diferentes tipos de argilas hidrofílicas em dispersões aquosas de poliuretanos para formação de nanocompósitos / Study of incorporation of different hydrophilic clays in nanocomposites of water born polyurethanes
Neste trabalho foram sintetizados nanocompósitos à base de poliuretanos em dispersão aquosa (NWPUs) e argilas hidrofílicas do tipo montimorilonita (MMT) de natureza sódica e cálcica. Os monômeros empregados na síntese foram: poli(glicol propilênico) (PPG); copolímero em bloco à base de poli(glicol etilênico) e poli(glicol propilênico) (EG-b-PG),
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 15/07/2009
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26. Estudo do envelhecimento de poliuretanos aplicados na indústria de petróleo / Study of polyurethanes ageing applied to offshore industry
A indústria do petróleo é um dos setores com maior número de sistemas produtivos empregando alta tecnologia. O Brasil é mundialmente renomado como um líder na extração de petróleo, em águas profundas e ultraprofundas. Dentro da cadeia produtiva, grande parte do petróleo e do gás produzido é escoado através de dutos flexíveis que conectam os po
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 06/05/2009
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27. Determinación de la densidad de entrecruzamiento de poliuretanos obtenidos a partir de aceite de ricino modificado por transesterificación
Two series of polyols were obtained from castor oil modified by transesterification with various amounts of pentaerythritol and glycerol. The resultant polyol properties were characterized as a function of the hydroxyl functionality. Polyurethane elastomers (PU) were synthesized from the two series of polyols obtained. The crosslink density of those polyuret
Polímeros. Publicado em: 2009
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28. Biomaterial based novel polyurethane adhesives for wood to wood and metal to metal bonding
Polyurethane adhesives made from synthetic chemicals are non-biodegradable, costly and difficult to find raw materials from local market. To avoid solid pollution problem, cost effectiveness and easy availability of raw materials, biomaterials based polyurethane adhesives are used in current industrial interest. Direct use of castor oil in polyurethane adhes
Materials Research. Publicado em: 2009
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29. Dispersiones acuosas de poliuretano bloqueado: una alternativa como agente curtiente
Two types of crosslinking agents blocked polyurethanes were synthesized and evaluated as tanning agents of bovine skins. The results of the synthesis of aqueous dispersions of blocked polyurethane (DPU’s) are presented. They were based on prepolymers from the reaction of the aliphatic diisocyanates H12MDI 4,4’-methylenebis(cyclohexyl isocyanate) and HDI
Polímeros. Publicado em: 2008-06
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30. Sintese de poli (esteres-uretanas) a base de poliois de poli (hidroxibutirato) e poli (caprolactona) / Synthesis of poly (ester-urethanes) from poly (hydroxybutyrate) and poly (caprolactone)
The synthesis of polyurethanes containing PHB and PCL blocks aims to obtain materials with controlled mechanical properties maintain biodegradable and biocompatible polymers such as poly(hidroxybutyrate) (PHB) and poly(caprolactone) (PCL) have been largely studied. The synthesis of polyurethanes containing blocks of PHB and PCL aims to obtain materials with
Publicado em: 2008
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31. Uso do silicone e poliuretano na uretroplastia dorsal: estudo experimental em coelhos / The silicone and polyurethane used in dorsal on lay urethroplasty: experimental study in rabbits
BACKGROUND: Actually, the treatment of urethral stenosis employs biological grafts, usually autologous grafts. The success with synthetic biomaterials in others medical specialtys motivated the search of these materials in urethral reconstruction. The knowledge about the silicone mamarian prosthesis covered with polyurethane foam reduces capsular contracture
Publicado em: 2008
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32. Attachment of inorganic moieties onto aliphatic polyurethanes
Polyurethanes have been used in a series of applications due basically to their versatility in terms of controlling the behavior by altering basically the type of reagents used. However, for more specific and advanced applications, such as in membranes, biomaterials and sensors, well-organized and defined chemical functionalities are necessary. In this work,
Materials Research. Publicado em: 2007-06
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33. Estudo da influência do teor de segmentos hidrofílicos na síntese de poliuretanos dispersos em água / Study of the influence of the hydrophilic segments content in the synthesis of waterbome polyurethanes
Considerações ambientais têm aumentado a pesquisa e o desenvolvimento de sistemas poliméricos aquosos para diversos tipos de aplicações, principalmente como revestimentos. Nesta dissertação, foram sintetizadas formulações não-poluentes à base de poliuretanos dispersos em água (PUDs), com 40% de teor de sólidos, na ausência de solventes orgâni
Publicado em: 2007
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34. Preparação de resinas de poliuretana à base de óleo de mamona e dietanolamina
The aim of this work was the preparation of polyols from reactions between castor oil and dietanolamine to increase the hydroxyl content and the network degree in the products to application in electronic devices. The polyols and the mixtures obtained were characterized by nuclear magnetic ressonance. Castor oil (CO) is a natural triglyceride - based polyol
Publicado em: 2007
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35. Optimization of Polyurethanes for Protection of Flexible Pipes Subject at Abrasion Wear / Otimização de poliuretanos para protetores de linhas flexíveis sujeitos ao desgaste abrasivo
n the last year the Petrobras Company gone self sufficiency of Brazil in the production of petroleum, Its take great effort to achieve technology in the exploration of deeper oil-well offshore. The extraction of petroleum deeper off-shore is make through flexible pipes that has multi layers of metal materials and polymeric materials, connected semi-submersib
Publicado em: 2007
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36. OtimizaÃÃo de poliuretanos para protetores de linhas flexÃveis sujeitos ao desgaste abrasivo / Optimization of Polyurethanes for Protection of Flexible Pipes Subject at Abrasion Wear
n the last year the Petrobras Company gone self sufficiency of Brazil in the production of petroleum, Itâs take great effort to achieve technology in the exploration of deeper oil-well offshore. The extraction of petroleum deeper off-shore is make through flexible pipes that has multi layers of metal materials and polymeric materials, connected semi-submers
Publicado em: 2007