Journal articles: 'Resinas epoxi'

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Credali, Lino, and Gianluca Ussia. "Nuevos desarrollos en la aplicación de materiales compósitos en construcciones: sistemas de resinas a base acuosa "bet on tex ipn" y su aplicación en tecnologías FRP y FRCM." Alternativas 17, no. 3 (February 1, 2017): 142–56. http://dx.doi.org/10.23878/alternativas.v17i3.235.

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Los materiales compósitos formados principalmente por fibras de carbón y matrices de resinas poliméricas epoxi han sido utilizados por más de 30 años, alcanzando un alto nivel técnico en todo el mundo. A pesar de los extraordinarios resultados obtenidos con este tipo de resinas, algunas de sus características han sido fuertemente criticadas, teniendo como consecuencia algunas limitaciones en su aplicación y en la definición de soluciones de diseño. Las restricciones de las aplicaciones de las tecnologías basadas en resinas epoxi se deben principalmente a su ausencia de permeabilidad a la humedad, su alta sensibilidad a la humedad durante la aplicación, sus escasas propiedades térmicas con un valor de T.g. de 100 °C y su falta de resistencia a la quema.En nuestra empresa Ardea, hemos llevado a cabo una larga investigación sobre este tema y hemos introducido en el mercado de la construcción un nuevo sistema de resinas a base acuosa, Betontex IPN, los cuales están basados en estructuras poliméricas interpenetradas. Betontex IPN es un sistema de resinas de dos componenes: el Componente A es una sustancia polimérica emulsionada en agua y el Componente B es una segunda fase polimérica presente en un relleno inorgánico microcristalino. Después del mezclado e homogenizado, el material resultante es permeable a la humedad y resistente a la quema (de acuerdo a la normativa UNI 9177), con una resistencia térmica más allá de los 180 °C y una temperatura de degradación mayor a 600 °C.Las propiedades de éstas resinas en combinación con refuerzos de fibras de carbón, aramida y vidrio han sido evaluadas en estructuras de mampostería y concreto. Las resinas IPN muestran una gran gama de propiedades interesantes y pueden ser usadas como tecnología FRP en lugar de las resinas epoxi, o como tecnología FRCM, en donde el IPN actúa como promotor de adhesión entre las fibras y el mortero. Otras propiedades de las resinas IPN incluyen buenas propiedades mecánicas, buena adhesión a las fibras, alta compatibilidad y buena adhesión a morteros de cal, concreto, mampostería, madera y mármol. El sistema de resinas IPN puede también ser usado en condiciones húmedas y aplicado sobre superficies mojadas. En los últimos años, las nuevas tecnologías IPN han sido ampliamente usadas para la rehabilitación de estructuras dañadas como consecuencia de los terremotos de 2009 (L’Aquila, Italia) y 2012 (Emilia Romagna, Italia).

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López-Fabal, M. F., C. Pérez-Lamela, J. M. Creus-Vidal, and P. Paseiro-Losada. "DETERMINATION OF BISPHENOL A DIGLYCIDYL ETHER IN PLASTIC MATERIALS BASED ON EPOXY RESINS DETERMINACIÓN DEL BISFENOL A DIGLICIDIL ÉTER EN ENVASES ALIMENTARIOS ELABORADOS CON RESINAS EPOXI DETERMINACIÓN DO BISFENOL A DIGLICIDIL ÉTER EN ENVASES ALIMENTARIOS ELABORADOS CON RESINAS EPOXI." Ciencia y Tecnologia Alimentaria 3, no. 1 (December 2000): 6–12. http://dx.doi.org/10.1080/11358120009487642.

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Walz, Kurt. "Aplicación de las resinas epoxi para revestimientos y juntas de hormigón, en los Estados Unidos." Materiales de Construcción 13, no. 112 (December 19, 2016): 39. http://dx.doi.org/10.3989/mc.1963.v13.i112.2159.

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Bosch Panadero, Enrique, Sebastian Mas Fontao, Alberto Ruiz Priego, Jesús Egido, and Emilio González Parra. "Bisfenol (A) una toxina a tener en cuenta en el enfermo renal en hemodiálisis." Revista Colombiana de Nefrología 4, no. 1 (March 15, 2017): 57. http://dx.doi.org/10.22265/acnef.4.1.256.

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Muchas toxinas urémicas son originadas como consecuencia del catabolismo proteico por la flora intestinal. El metabolismo de aminoácidos aromáticos origina residuos de tipo fenólico. De estas toxinas, la más estudiada es el p-cresol, que se asocia a la función renal y daño vascular. El Bisfenol A (BPA) es una molécula exógena de características semejantes a estas toxinas urémicas aromáticas. El BPA es un disruptor endocrino estrogénico que se encuentra en latas de conserva, botellas de plástico, resinas epoxi y en algunos dializadores. Esta molécula se acumula en pacientes que tienen deteriorada la función renal. Estudios observacionales han demostrado que una exposición a BPA está vinculada, entre otras muchas, a lesión renal y cardiovascular en los seres humanos; en estudios en animales se ha descrito un vínculo causal. Los riñones con función renal normal excretan rápidamente BPA, pero una excreción insuficiente en pacientes con ERC da lugar a la acumulación del BPA en el organismo.

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Paz Oliveira, Geisyane De Castro, João Victor Silva Araújo, Aírton Mendes Conde Junior, and Kelly Palombit. "Bisfenol A: Possíveis Efeitos e Danos ao Organismo - Revisão de Literatura." Jornal Interdisciplinar de Biociências 2, no. 2 (December 20, 2017): 11. http://dx.doi.org/10.26694/jibi.v2i2.5699.

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O bisfenol A (BPA) é um produto químico, amplamente utilizado para a produção de policarbonatos e resinas epoxi. O BPA é encontrado principalmente em mamadeiras, tubulações de água, recipientes de armazenamento de alimentos e garrafas plásticas, sendo assim, o monômero mais comum ao contato alimentar. Os seres humanos são expostos diariamente a uma grande quantidade dessa substância, cujos efeitos podem ser nocivos a saúde humana. Sendo assim, reuniram-se informações de estudos relacionados acerca da exposição ao BPA, onde o objetivo foi analisar os efeitos dessa substância no organismo. Para a realização deste trabalho, buscaram-se informações nos periódicos eletrônicos Google Acadêmico, PubMed e Scielo, selecionando-se artigos publicados em periódicos nacionais e internacionais, publicados nos últimos 15 anos. Os descritores de assunto utilizados foram: Bisphenol A, Digestive System, Gastrointestinal Tract, Enteric Nervous System e Small Intestine. A presente revisão de literarura demonstrou que o BPA atua de diversas formas sobre a organismo, principalmente sobre os sistemas endócrino, reprodutor e nervoso central. O trato gastrintestinal, local de primeiro contato do BPA ingerido na dieta, merece maior atenção. Apesar da literatura apresentar relatos científicos atuais sobre o efeito do BPA no sistema digestório, características mais específicas deste sistema, necessitam de uma discussão mais ampla com realizações de novas pesquisas e publicações.

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Conceição, Rafael Novaes da, and João Sinézio de Carvalho Campos. "Avaliação das propriedades elétricas de barras estatóricas fabricadas com resina do tipo éter diglicidílico do bisfenol F (DGEBF) contendo nanopartículas de silica." Polímeros 26, no. 3 (August 4, 2016): 262–68. http://dx.doi.org/10.1590/0104-1428.2110.

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Resumo O presente trabalho visa apresentar resultados da aplicação de uma resina epóxi bisfenólica (DGEBF) à base de nanopartículas de sílica (RN) e comparar suas propriedades com a resina convencional de referência epóxi bisfenólica (DGEBA) (RE), atualmente utilizada. Neste sentido fabricaram-se protótipos de barras estatórica, destinadas a hidrogeradores, através do sistema VPI (Vácuo-Pressão-Impregnação) e avaliaram-se as propriedades elétricas pelas técnicas de fator de dissipação e envelhecimento acelerado. Dentre os resultados para as resinas observou-se que: (i) o fator de dissipação e de envelhecimento são praticamente os mesmos para ambas as resinas; (ii) o valor de tip-up resultaram em 0,014% para RE e 0,020% para a resina RN e (iii) a estimativa do tempo de vida útil esta em cerca de 40 anos, o que é aplicável para a maioria das aplicações industriais. Neste sentido sugere-se que a resina RN pode ser uma alternativa a resina RE, com um desempenho elétrico equivalente.

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Paiva, Jane M. F. de, Sérgio Mayer, Geraldo M. Cândido, and Mirabel C. Rezende. "Avaliação da temperatura de transição vítrea de compósitos poliméricos reparados de uso aeronáutico." Polímeros 16, no. 1 (March 2006): 79–87. http://dx.doi.org/10.1590/s0104-14282006000100016.

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Este trabalho mostra a avaliação da temperatura de transição vítrea (Tg), por DMTA, de três famílias de compósitos poliméricos reparados, tendo como laminados base tecidos de fibras de carbono/resina epóxi modificada com elastômero (F584), vidro/resina epóxi (F161) e aramida/resina epóxi (F161). Os compósitos foram laminados manualmente por processo convencional e curados em autoclave de indústria aeronáutica. Posteriormente, danos foram simulados sendo, em seguida, reparados adotando-se a técnica de sobreposição de camadas de pré-impregnados de resina epóxi (F155), com adição de filme adesivo de epóxi (FM 73). As curvas DMTA mostram os efeitos da combinação de diferentes sistemas de resinas na Tg e, conseqüentemente, na temperatura de serviço do componente reparado. O material de reparo utilizado, baseado em pré-impregnados com resina epóxi F155 e filme adesivo de epóxi, provocou a redução da Tg dos compósitos reparados. Para os laminados base com tecido de fibras de carbono e vidro foram verificadas reduções de aproximadamente 30 °C na Tg. Este efeito foi mais pronunciado (redução de aproximadamente 40 °C) quando o laminado reparado de aramida foi submetido a condicionamento higrotérmico a temperatura e umidade elevadas. Esta redução na Tg dos laminados reparados é atribuída à migração do adesivo para o pré-impregnado de resina epóxi F155 utilizado no reparo, durante o processo de cura, e à plasticização do sistema polimérico pela água, durante o condicionamento higrotérmico. A redução da Tg leva a uma conseqüente redução da temperatura de serviço do compósito polimérico reparado.

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Gouveia, Gabriel Amal Rebelo, Márcio C. S. Filho, and Santiago M. Lugones. "COMPRESSÃO DE MATERIAL COMPÓSITO – RESINA PARA LAMINAÇÃO (AERONÁUTICA X AUTOMOBILÍSTICA)." CIMATech 1, no. 6 (December 4, 2019): 150–61. http://dx.doi.org/10.37619/issn2447-5378.v1i6.207.150-161.

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No presente trabalho foram realizados testes de compressão com o propósito de obter o comportamento e os parâmetros de compressão mais importantes de diferentes resinas para serem utilizados em simulações estruturais em diferentes contextos que envolvam efeitos de flambagem. Pretende-se gerar um banco de dados do comportamento da resina epóxi, amplamente utilizada em aeronáutica. A resina automobilística é o outro alvo do trabalho devido a seus benefícios econômicos.

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Bertolini, Marília da Siva, Diego Henrique de Almeida, Laurenn Borges de Macedo, Felipe Hideyoshi Icimoto, Fabiane Salles Ferro, André Luis Christoforo, and Francisco Antonio Rocco Lahr. "Emprego de resina epóxi em vigas danificadas de madeira de Pinus elliottii." Ambiente Construído 14, no. 3 (September 2014): 121–29. http://dx.doi.org/10.1590/s1678-86212014000300010.

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A utilização da madeira em estruturas está vinculada a condições que permitam sua utilização por muitos anos sem a perda de suas propriedades de resistência e de rigidez. Entretanto, por se tratar de material natural, as estruturas em madeira projetadas podem estar sujeitas ao ataque de agentes biológicos, ação de intempéries, entre outros fatores, requerendo soluções na forma de reparo ou reforço. O presente trabalho objetivou investigar a influência do uso de resina epóxi como agente reparador em vigas danificadas de madeira de Pinus elliottii no cálculo do produto de rigidez à flexão. Para tanto, foi realizado um planejamento experimental completo, tendo a posição dos defeitos provocados (central ou laterais), o uso ou não da resina nos defeitos, e a posição desses defeitos (superior - compressão ou Inferior - tração) como fatores. Os resultados da análise estatística revelaram que o uso da resina epóxi nas regiões danificadas das vigas apresentaram valores do produto de rigidez na flexão significativamente superiores quando comparados com as vigas da condição com defeito e sem a resina epóxi. Mesmo sendo significativo o uso da resina nas regiões danificadas, o produto de rigidez à flexão das vigas reparadas foi inferior ao produto de rigidez à flexão das vigas sem defeito (referência), evidenciando a necessidade de outros estudos com outras resinas e outros materiais visando à recuperação total da rigidez da peça de madeira danificada.

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Souza, Christiane Sales Reis de, José Maria Fernandes Marlet, Andreza de Moura Cardoso, and Mirabel Cerqueira Rezende. "Estudo do comportamento térmico de laminados carbono/epóxi submetidos a múltiplos ciclos térmicos." Polímeros 26, spe (January 19, 2016): 8–15. http://dx.doi.org/10.1590/0104-1428.1769.

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Resumo Este trabalho apresenta um estudo comparativo dos comportamentos térmicos de três famílias de laminados de fibra de carbono/resina epóxi, submetidas a múltiplos ciclos térmicos, via análises termogravimétricas e dinâmico-mecânicas. Este estudo procura aliar a possibilidade de utilização de retalhos de pré-impregnados de fibra de carbono com resina epóxi - um material nobre na indústria aeronáutica, por meio da comparação do comportamento térmico de um laminado preparado com retalhos de pré-impregnados (laminado R), com outros dois laminados, sendo um manufaturado com prepreg comercial (laminado A) e um terceiro obtido por impregnação manual de reforço seco de fibra de carbono com resina epóxi (laminado B). Os laminados curados a 180 °C foram submetidos a múltiplos ciclos térmicos, totalizando 40, 100 e 300 h de exposição na temperatura máxima de 180 °C. As análises termogravimétricas mostram que os laminados submetidos às múltiplas ciclagens apresentam estabilidade térmica na temperatura de 180 °C, com perda de massa relativa à umidade absorvida pelos laminados. As análises dinâmico-mecânicas evidenciam que as múltiplas ciclagens térmicas afetam pouco ou até aumentam as temperaturas de transição vítrea dos sistemas de resinas epóxis estudados. A partir dos resultados obtidos pode-se afirmar que os laminados submetidos às múltiplas ciclagens térmicas apresentam estabilidade térmica suficiente para serem utilizados, por exemplo, em ferramentais de cura de componentes aeronáuticos.

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Oliveira, Alexsandro, Cristiane Miotto Becker, and Sandro Campos Amico. "Avaliação das características da resina epóxi com diferentes aditivos desaerantes." Polímeros 25, no. 2 (April 2015): 186–91. http://dx.doi.org/10.1590/0104-1428.1661.

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Este trabalho tem por objetivo a busca por técnicas alternativas para diminuir a incidência de vazios em resinas poliméricas e, por consequência, em materiais compósitos. Foram produzidas formulações diferentes utilizando resina epóxi à base de éter diglicidílico do Bisfenol A, endurecedor de poliamina alifática com e sem a adição de diferentes aditivos desaerantes a base de éteres e ésteres modificados. As formulações produzidas foram submetidas a condições extremas de agitação e processamento, sendo posteriormente avaliadas quanto a incidência de bolhas e vazios, densidade, propriedades mecânicas, morfológicas e térmicas. Os resultados foram bastante positivos quanto à diminuição da quantidade e do tamanho de poros pela utilização de técnicas de desgaseificação a vácuo e pelo uso de aditivos desaerantes.

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Kim, Jung Gon, Kyoung Hoon Shin, Ho Seok Ryu, and Jae Wook Lee. "Monitoring the Change of Viscosity during Cure Reaction of Epoxy Resins with Resin Position Sensor." Journal of Reinforced Plastics and Composites 21, no. 2 (January 2002): 139–52. http://dx.doi.org/10.1177/0731684402021002353.

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It was required that the fundamental understanding of the resin’s rheological properties, such as viscosity, gel point and degree of cure are known during the processing of epoxy resin. In order to monitor these properties in-situ, a sensor system that can measure the viscosity changes during cure is needed. The resin position sensor (RPS) based on DC conductometry has been able to measure the ionic contents and electrical conductivity of most organic resins. Complex viscosity and electrical resistance were measured simultaneously during the cure of diglycidyl ether of bisphenol-A (DGEBA) epoxy resin with polyamide by mounting the RPS on the upper plate of rotational rheometer. To correlate the viscosity with the resistance, the rheological model for the viscosity changes and the electrical model for the resistance changes were used. From the results, the interrelationship of viscosity and resistance of epoxy resin could be confirmed.

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Bashta, Bogdana, Olena Astakhova, Olena Shyshchak, and Michael Bratychak. "Epoxy Resins Chemical Modification by Dibasic Acids." Chemistry & Chemical Technology 8, no. 3 (September 1, 2014): 309–16. http://dx.doi.org/10.23939/chcht08.03.309.

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Zhao, Wenzhe, Le An, and Shujuan Wang. "Recyclable High-Performance Epoxy-Anhydride Resins with DMP-30 as the Catalyst of Transesterification Reactions." Polymers 13, no. 2 (January 18, 2021): 296. http://dx.doi.org/10.3390/polym13020296.

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Epoxy-anhydride resins are widely used in engineering fields due to their excellent performance. However, the insolubility and infusibility make the recycling of epoxy resins challenging. The development of degradable epoxy resins with stable covalent networks provides an efficient solution to the recycling of thermosets. In this paper, 2,4,6-tris(dimethylaminomethyl)phenol (DMP-30) is incorporated into the epoxy-glutaric anhydride (GA) system to prepare high-performance epoxy resins that can be recycled below 200 °C at ordinary pressure via ethylene glycol (EG) participated transesterification. The tertiary amine groups in DMP-30 can catalyze the curing reaction of epoxy and anhydride, as well as the transesterification between ester bonds and alcoholic hydroxyl groups. Compared with early recyclable anhydride-cured epoxy resins, the preparation and recycling of diglycidyl ether of bisphenol A (DGEBA)/GA/DMP-30 systems do not need any special catalysts such as TBD, Zn(Ac)2, etc., which are usually expensive, toxic, and have poor compatibility with other compounds. The resulting resins have glass transition temperatures and strengths similar to those of conventional epoxy resins. The influences of GA content, DMP-30 content, and temperature on the dissolution rate were studied. The decomposed epoxy oligomer (DEO) is further used as a reaction ingredient to prepare new resins. It is found that the DEO can improve the toughness of epoxy resins significantly. This work provides a simple method to prepare readily recyclable epoxy resins, which is of low-cost and easy to implement.

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Hu, Fang. "Development of technology to industrialise the production of 80000 MTPY epoxy resins." Pigment & Resin Technology 44, no. 3 (May 5, 2015): 179–86. http://dx.doi.org/10.1108/prt-05-2014-0044.

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Purpose – The purpose of this paper is to establish a technology that is suitable for the production of the 80,000 MTPY series of epoxy resins on an industrial scale. Design/methodology/approach – This paper introduces the synthesis and processing of epoxy resins, including liquid epoxy resins (DGEBA) (E-51 and E-44), brominated bisphenol A-based epoxy resins (EX-23-80A), semisolid epoxy resins based on DGEBA (E-39D) and solid epoxy resins based on DGEBA (E-21). The study analyses the theoretical raw materials of epoxy resins per tonne, and lists an example of a distributed control system (DCS) to explain that the production process of 80,000 MTPY epoxy resins can be automated. Findings – A two-step method was used to produce either E-51 or E-44 sequentially in the pre-reactor, the reactor, the recycling kettle, refining kettle (1), the refining kettle (2) and the desensitizing kettle or the falling-film evaporator. An advancement process was adopted to manufacture EX-23-80A, E-39D and E-21 using E-51 as a raw material in the predominating kettle and the mixing kettle, the adding kettle (1) and the adding kettle (2), separately. All the processes were controlled automatically by DCS to yield the products. Originality/value – The results support the assertion that the technology developed by the authors ' company to produce 80,000 MTPY epoxy resins results in fewer side reactions and higher yield production.

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Brzozowski, Zbigniew K., Sylwia Staszczak, Pawel Koziol, Wojciech Zatorski, and Dariusz Bogdal. "Development and Characterization of Novel Fore Safe Epoxy Resins." Chemistry & Chemical Technology 3, no. 4 (December 15, 2009): 269–76. http://dx.doi.org/10.23939/chcht03.04.269.

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The curing system for newly developed solid state fire safe epoxy resins using dicyandiamide (DICY) was introduced. Composites of epoxy resins obtained from diglycidyl ether of 1,1-dichloro-2,2bis(4-hydroxyphenyl)ethylene bisphenol-C (BPC) and bisphenol-A (BPA) epoxy resins in the reaction with BPC and BPA and DICY hardener were studied. Solid epoxy resins were synthesised by the use of two different heating methods: conventional and microwave reactor. The quantities of DICY additions were 0.5–5.0 %, optimum was found to be 3 %. Limited oxygen index (OI) tests for different epoxy resins and addition of flame – retardants were carried out. The highest value of OI was 34.6. As additional flame-retardants were used zinc stannates (ZS, ZHS). Evident OI increase was noted from 27.0 for classical epoxies, 34.6 for BPC cured epoxies and 44 for cured composites with the addition of Zn/Sn flame-retardants.

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TANAKA, Ryohei. "Epoxy Resins." Journal of the Japan Society of Colour Material 64, no. 10 (1991): 655–65. http://dx.doi.org/10.4011/shikizai1937.64.655.

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Tian, Xiu Juan. "Thermal Stabilities and the Thermal Degradation Kinetics Study of the Flame Retardant Epoxy Resins." Advanced Materials Research 1053 (October 2014): 263–67. http://dx.doi.org/10.4028/www.scientific.net/amr.1053.263.

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Thermal stability and thermal degradation kinetics of epoxy resins with 2-(Diphenylphosphinyl)-1, 4-benzenediol were investegated by thermogravimetric analysis (TGA) at different heating rates of 5 K/min, 10 K/min, 20 K/min and 40 K/min. The thermal degradation kinetic mechanism and models of the modified epoxy resins were determined by Coast Redfern method.The results showed that epoxy resins modified with the flame retardant had more thermal stability than pure epoxy resin. The solid-state decomposition mechanism of epoxy resin and the modified epoxy resin corresponded to the controlled decelerating ځ˽̈́˰̵̳͂͆ͅ˼˰̴̱̾˰̸̵̈́˰̵̸̳̱̹̽̾̓̽˰̶̳̹̾̈́̿̾̓ͅ˰̶˸ځ˹˰̵̵͇͂˰̃˸́˽ځ˹2/3. The introduction of phosphorus-containing flame retardant reduced thermal degradation rate of epoxy resins in the primary stage, and promote the formation of carbon layer.

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Bratychak, Michael, Victoria Kochubei, Olena Shust, and Oleh Shyshchak. "Cross-linking of Epoxy-Oligoesteric Mixtures in the Presence of Fluorine-Containing Epoxy Resins." Chemistry & Chemical Technology 5, no. 1 (March 15, 2011): 41–48. http://dx.doi.org/10.23939/chcht05.01.041.

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Vashurkin, Dmitry V., Georgiy V. Malkov, Sergei V. Karpov, Nilson O. Garifullin, and Artur T. Kapasharov. "The Method of the Extent of Epoxy-Amine Cure Reaction Determination by near Infra-Red Spectroscopy." Key Engineering Materials 816 (August 2019): 180–86. http://dx.doi.org/10.4028/www.scientific.net/kem.816.180.

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The aim of this work is development of method to determine the conversion of epoxy groups in the epoxy amine resins based on the epoxy oligomer ED-20 and hardener DDM. The studies were carried out in the NIR range. The mathematical division of the spectrum of the resins into individual peaks was used and concentrations of the functional groups were calculated on them. The dependence of the maximum conversion of epoxy groups in the resins after curing at 140 оС was obtained.

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Vyhnánková, Michaela, Jakub Hodul, and Jiří Bydžovský. "Issue of Epoxy-Based Coatings System Crystallization and Effect of Partial Crystallinity on Mechanical Parameters." Key Engineering Materials 776 (August 2018): 147–52. http://dx.doi.org/10.4028/www.scientific.net/kem.776.147.

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Crystallization of bisphenol A-based and bisphenol F-based epoxy resins is the common property of the oligomers. However, producers of paints, coatings and other systems based on these epoxy resins are making efforts to slow down the crystallization process as much as possible. Thereby the shelf life is prolonged, while improving the competitiveness of their products. The main topic is the generalization of factors influencing the crystallization process of bisphenol A-based and bisphenol F-based epoxy resins, the validation of new approaches to possibility of influencing their crystallization process, and the determination of possibility of using a certain degree of crystallinity of bisphenol A-based and bisphenol F-based epoxy resins when preparing and producing paint and coating systems. Two types of the epoxy resins in formulations of paint and coating and other systems, namely: diglycidyl ether of bisphenol A (DGEBA) and diglycidyl ether of bisphenol F (DGEBF) were used. The tendency to crystallize not only for the pure epoxy resins, but also various mixtures with reactive diluents, fillers, etc. was determined according to the standard ISO 4895 Plastics – Liquid epoxy resins – Determination of tendency to crystallize. Furthermore, the crystallinity of individual samples was determined. The effectiveness of potentially active nucleating agents such as precipitated calcium carbonate, DGEBA, and DGEBF crystals, etc. was selected and tested according to the ISO 4895 standard. The effectiveness of potentially active admixtures with crystallization retardation effect was selected and tested according to the ISO 4895 standard. Selected samples of the epoxy resins with a specified degree of crystallinity were cured with 3-aminomethyl-3,5,5-trimethylcyclohexylamine (IPD) based crosslinking agent. Mechanical parameters such as compressive strength and flexural strength were determined. The influence of crystallinity on selected mechanical parameters was also observed.

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Ito, Yumiko, Daisuke Aoki, and Hideyuki Otsuka. "Functionalization of amine-cured epoxy resins by boronic acids based on dynamic dioxazaborocane formation." Polymer Chemistry 11, no. 33 (2020): 5356–64. http://dx.doi.org/10.1039/d0py00048e.

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23

Ahmed, Murtala Musa, Noor Shawal Nasri, Rahmat Mohsin, Usman Dadum Hamza, and Jibril Mohammed. "Preparation of Epoxy-Novolac Resin Binder Using Phenolic Rich Fractions of Biomass Pyrolytic Oil as Partial Substitute of Phenol." Applied Mechanics and Materials 554 (June 2014): 101–5. http://dx.doi.org/10.4028/www.scientific.net/amm.554.101.

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Epoxy resins are among the basic components for coatings manufacture but because of their cost and environment effects, some environmental protection regulations have restricted the use of chemicals considered toxic. The potential of using phenolic rich fractions of bio-oil derived from the pyrolysis of a sustainable agricultural waste for epoxy resin synthesis was investigated. Epoxy resins with different concentration of water-insoluble heavy fraction were synthesized. The bio-oil, heavy fraction and prepared resins were later characterized using Fourier Transform Infra-Red (FTIR), Gas Chromatography Mass Spectrometry (GC-MS) and Differential Scanning Calorimetry (DSC). FTIR and GC-MS results confirmed the presence of phenols on both the bio-oil and heavy fraction with heavy fraction having a higher concentration. DSC analysis showed a corresponding increase on curing time of the resins with increased quantity of phenolic rich components. FTIR analysis of the resin indicated high-ortho structure. Utilization of bio-oil as a source of phenol for epoxy resins manufacture would significantly reduce the cost and negative environmental effects of the current resins.

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Sag, Jacob, Daniela Goedderz, Philipp Kukla, Lara Greiner, Frank Schönberger, and Manfred Döring. "Phosphorus-Containing Flame Retardants from Biobased Chemicals and Their Application in Polyesters and Epoxy Resins." Molecules 24, no. 20 (October 17, 2019): 3746. http://dx.doi.org/10.3390/molecules24203746.

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Phosphorus-containing flame retardants synthesized from renewable resources have had a lot of impact in recent years. This article outlines the synthesis, characterization and evaluation of these compounds in polyesters and epoxy resins. The different approaches used in producing biobased flame retardant polyesters and epoxy resins are reported. While for the polyesters biomass derived compounds usually are phosphorylated and melt blended with the polymer, biobased flame retardants for epoxy resins are directly incorporated into the polymer structure by a using a phosphorylated biobased monomer or curing agent. Evaluating the efficiency of the flame retardant composites is done by discussing results obtained from UL94 vertical burning, limiting oxygen index (LOI) and cone calorimetry tests. The review ends with an outlook on future development trends of biobased flame retardant systems for polyesters and epoxy resins.

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Chatterjee, Gautam, Israel Cabasso, and Johannes Smid. "Radiopaque epoxy resins." Journal of Applied Polymer Science 55, no. 6 (February 7, 1995): 851–56. http://dx.doi.org/10.1002/app.1995.070550602.

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Choudhary, Veena, Seema Agarwal, and I. K. Varma. "Multifunctional epoxy resins." Journal of Applied Polymer Science 49, no. 10 (September 10, 1993): 1751–58. http://dx.doi.org/10.1002/app.1993.070491006.

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27

Bratychak, Michael, Olena Shust, Olena Astakhova, and Olena Shyshchak. "Chemical Modification of Dianic Epoxy Resin by Fluorine-Containing Alcohols." Chemistry & Chemical Technology 3, no. 3 (September 15, 2009): 191–96. http://dx.doi.org/10.23939/chcht03.03.191.

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New epoxy resins with fluorine atoms have been synthesized via chemical modification of dianic epoxy resin with fluorine-containing alhocols-telomers C7, C9 and C13, using benzyltriethylammonium chloride and KOH as a catalyst system. Their characteristics have been examined. The structure of synthesized products has been confirmed by IR-spectroscopy. It has been shown that new epoxy resins may be used as active plasticizers for industrial epoxy resin.

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Zhang, Yi, Li Yuan, Yanli Su, Aijuan Gu, Shenmei Wu, and Guozheng Liang. "Preparation and property of epoxy resins-penetrated aligned carbon nanotube bundle hybrid microcapsules for self-healing polymers." High Performance Polymers 29, no. 4 (May 11, 2016): 396–410. http://dx.doi.org/10.1177/0954008316645847.

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The epoxy resins-penetrated aligned carbon nanotube bundle (ACNTsB) hybrid system (epoxy@ACNTsB) was prepared by soaking ACNTsB in the acetone solution of epoxy resins. Epoxy@ACNTsB was encapsulated in aqueous solution containing an amine curing agent to prepare hybrid microcapsules (MCs). The structure and morphology of MCs were characterized by Fourier transform infrared spectroscopy, scanning electronic microscopy, transmission electron microscopy, and laser scanning confocal microscopy. The thermal properties of MCs were carried out by differential scanning calorimetry and thermogravimetric analysis. The solvent resistance of MCs in acetone was also investigated. The results show that MCs exhibit high initial decomposition of temperatures (266°C). The content of epoxy resin in MCs is about 74% and the polymer film thickness of MCs is from 1 to 2 μm. MCs show high thermal and chemical stability below 200°C and excellent solvent resistance. MCs embedded in cyanate ester (CE) resins can significantly toughen the matrix. The fracture MCs can release the epoxy resins under heating condition, and the released epoxy resins can react with the reactive –OCN group/triazine rings in the CE matrix to rebond the crack surfaces. When the temperature schedule of 100°C/1 h + 200°C/2 h is applied, 10–15 wt% MCs can recover from 82.7% to 99.8% of the original fracture toughness of CE matrix.

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Zhang, Xugang, Bin Zhang, Mingming Sun, Jianhui Li, Lei Wang, and Chuanli Qin. "Miscibility, morphology, mechanical, and thermodynamic properties of epoxy resins toughened with functionalized core-shell nanoparticles containing epoxy groups on the surface." Pigment & Resin Technology 43, no. 1 (December 20, 2013): 8–18. http://dx.doi.org/10.1108/prt-03-2013-0022.

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Purpose – In order to obtain functionalized core-shell nanoparticles (CSNPs) as excellent toughening agents for epoxy resins. The paper aims to discuss these issues. Design/methodology/approach – Functionalized CSNPs containing epoxy groups on the surface were synthesized by emulsion polymerization with butyl acrylate as the core and methyl methacrylate copolymerizing with glycidyl methacrylate (GMA) as the shell. CSNPs were used as toughening agents for epoxy resins and their chemical structure was characterized by FT-IR. The morphology of modified epoxy networks (MEPN) was analyzed by SEM and TEM. Both the mechanical properties and thermodynamic properties were studied. Findings – The results show that nearly spherical CSNPs with the particle size of 50-100 nm are obtained. A certain amount of CSNPs are uniformly dispersed in epoxy resins by the grinding method and the MEPN shows the ductile fracture feature. The miscibility between CSNPs and epoxy matrix increases with the increase of GMA concentration which makes more bonds form between them. Epoxy resins toughened with 10 wt% CSNPs containing 10 wt% GMA show the best mechanical properties and the increase in tensile strength and impact strength of the MEPN is 13.5 and 59.7 percent, respectively, over the unmodified epoxy networks. And the improvement in impact strength is not accompanied with loss of thermal resistance. Practical implications – The MEPN can be used as high-performance materials such as adhesives, sealants and matrixes of composites. Originality/value – The functionalized CSNPs are novel and it can greatly increase the toughness of epoxy resins without loss of thermal resistance.

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Legocka, Izabella, Ewa Wierzbicka, Talal Al-Zahari, and Osazuwa Osawaru. "Modified halloysite as a filler for epoxy resins." Polish Journal of Chemical Technology 13, no. 3 (January 1, 2011): 47–52. http://dx.doi.org/10.2478/v10026-011-0036-3.

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Modified halloysite as a filler for epoxy resins The modification methods of halloysite and further applications of the modified mineral as a filler for epoxy resins have been presented. The advantage of ultrasound treatment prior to chemical modification with an organic compound in order to obtain a hybrid filler was confirmed. The analysis of the composites obtained with the use of the modified halloysite (3-5 wt.% range) as a filler for epoxy resins indicates an improved interphase interaction and mechanical properties in comparison to the composites based on neat halloysite.

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Rahmah, Mohammad, Syuhaimi Ab Rahman Mohammad, Mohamed Shaktur Khaled, Nawi Norwimie, and Faiza Mohd Ahmad. "Degradation Behaviour and Kinetics of UV Cured Epoxidised Soybean Oil Derivatives." Advanced Materials Research 230-232 (May 2011): 94–98. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.94.

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Green resins based from sustainable resources are a requirement nowadays to replace non environmental coatings. Low (VOC) content epoxy which competes with conventional well established coating and high price could be derived from oil. UV curable resin is typically low VOC systems and offer advantages of rapid ambient cross linking and more energy efficient. Epoxy resins must have fast curing and low shrinkage upon cure which will give advantages to devices performance but epoxy resins are expensive and hence renewable resources from vegetable or non food oil can be used as raw materials.

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Kobayashi, M., Y. Hatano, and B. Tomita. "Viscoelastic Properties of Liquefied Wood/Epoxy Resin and its Bond Strength." Holzforschung 55, no. 6 (November 6, 2001): 667–71. http://dx.doi.org/10.1515/hf.2001.108.

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Summary A new resin system, in which liquefied wood was reacted with various epoxy compounds, was previously developed. This paper reports the syntheses of two types of liquefied wood/epoxy resins with the ratio of liquefied wood to epoxy compounds (L/E ratio) of either 1/0.5 or 1/1. Furthermore, the viscoelastic properties obtained from the dynamic mechanical measurements of the cured resins and their adhesive bond properties measured as tensile shear strength are reported. The results from dynamic mechanical measurements indicated that the resins with a L/E ratio of 1/0.5 could be cured at 90°C, while the resins with L/E ratio of 1/1 were cured at 150°C. The resins cured with triethylene tetramine (TETA) at 150°C or 90°C had almost the same level of the normal adhesive shear strength as that of the commercial epoxy resin. The high level of adhesive shear strength of the resin cured at 150°C was maintained after the glued specimens were soaked in water at 60°C, while the share strength of the resins cured at 90°C was reduced by either the water soaking at 60°C or the cyclic boiling test.

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Tosti, Antonella, Liliana Guerra, Colombina Vincenzi, and Anna Maria Peluso. "Occupational Skin Hazards from Synthetic Plastics." Toxicology and Industrial Health 9, no. 3 (May 1993): 493–502. http://dx.doi.org/10.1177/074823379300900308.

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Epoxy and acrylic resins have numerous industrial applications but are also widely used in the household environment. These compounds are presently one of the most important sources of occupational contact dermatitis. Contact sensitization to epoxy resins is usually caused by the resin itself but hardeners or other additives, such as reactive diluents, plasticizers, fillers and pigments, can occasionally be responsible. Since completely cured epoxy resins are not sensitizers, epoxy resin sensitization is always due to the presence, in the final polymer, of uncured allergenic low molecular weight oligomers. Acrylates are now considered the fourth most common cause of contact sensitization due to resins. Unpolymerized monomers of acrylic compounds are known to be responsible for the contact allergy. Accelerators, inhibitors and catalysts, which are usually added to the acrylates to promote the polymerization process, can also sensitize. Both allergic and irritant contact dermatitis may be caused by exposure to epoxy or acrylic resins and their additives. Contact urticaria, allergic or irritant airborne contact dermatitis caused by volatile compounds, onychia and paronychia can also occur. From January of 1984 to May of 1992 we detected 39 cases of occupational allergic contact dermatitis to epoxy resin system substances and 11 cases of occupational contact sensitization to acrylic compounds. In our experience, the electronics industry as well as paint and glue related activities were the most important sources of epoxy sensitization. Dental materials and anaerobic sealants were found to be the most frequent acrylate sensitizers.

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Zarybnicka, Lucie, Jana Machotova, Radka Kopecka, Radek Sevcik, Martina Hudakova, Jaroslav Pokorny, and Jiri Sal. "Effect of Cyclotriphosphazene-Based Curing Agents on the Flame Resistance of Epoxy Resins." Polymers 13, no. 1 (December 22, 2020): 8. http://dx.doi.org/10.3390/polym13010008.

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Epoxy resins are characterized by excellent properties such as chemical resistance, shape stability, hardness and heat resistance, but they present low flame resistance. In this work, the synthesized derivatives, namely hexacyclohexylamino-cyclotriphosphazene (HCACTP) and novel diaminotetracyclohexylamino-cyclotriphosphazene (DTCATP), were applied as curing agents for halogen-free flame retarding epoxy materials. The thermal properties and combustion behavior of the cured epoxy resins were investigated. The obtained results revealed that the application of both derivatives significantly increased flame resistance. The epoxy resins cured with HCACTP and DTCATP exhibited lower total heat release together with lower total smoke production compared to the epoxy materials based on conventional curing agents (dipropylenetriamine and ethylenediamine). Comparing both derivatives, the HCACTP-cured epoxy resin was found to provide a higher flame resistance. The designed novel class of epoxy materials may be used for the preparation of materials with improved flame resistance properties in terms of flame spreading and smoke inhibition.

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Costa, Michelle L., Mirabel C. Rezende, and Luiz C. Pardini. "Métodos de estudo da cinética de cura de resinas epóxi." Polímeros 9, no. 2 (June 1999): 37–44. http://dx.doi.org/10.1590/s0104-14281999000200011.

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Nas últimas décadas tem-se estudado a cinética da reação de cura de resinas epóxi por meio de técnicas analíticas como por exemplo a calorimetria exploratória diferencial. O uso desta técnica permite utilizar vários métodos de estudo da cinética de cura, divididos em: métodos dinâmicos e isotérmicos, e cada pesquisador escolhe o que melhor se adapta às suas necessidades. O presente trabalho tem como objetivo orientar na escolha de qual método deve ser utilizado, em função dos sistemas poliméricos em estudo, bem como sumarizar os principais métodos utilizados, auxiliando, dessa forma, no estudo da cinética de cura de resinas epóxi.

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Yao, Da Hu, Yu Qing Zhang, and Joong Hee Lee. "Increasing Cryogenic Strength of Epoxy Resin Modified by Reactive Macroglycol." Applied Mechanics and Materials 52-54 (March 2011): 2056–59. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.2056.

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A bisphenol-A glycidol ether epoxy resin was toughened in cryogenic temperature using reactive macroglycol as modifiers. The properties of modified epoxy resin were characterized by SEM and DMA. Phase-separated structure formed during curing process in the PPG and PTMG modified epoxy resins system, and did not occurred in the PEO modified epoxy resins system. The impact strength of epoxy resin increased at both room temperature (RT) and cryogenic temperature (CT, 77 K) using PEO as modifier. The DMA results confirm that the introduction of PEO chains in the structure of the epoxy increases the mobility of the molecular segment of epoxy network at both RT and CT.

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Atta, Ayman M. "Epoxy Resin Based on Poly(ethylene terephthalate) Waste: Synthesis and Characterization." Progress in Rubber, Plastics and Recycling Technology 19, no. 1 (February 2003): 17–40. http://dx.doi.org/10.1177/147776060301900102.

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Aromatic epoxy resin based on poly(ethylene terephthalate), PET, was synthesised by glycolysis of PET with different ratios of diethanolamine or triethanolamine and manganese acetate as a catalyst. The glycolyzed products were reacted with epichlorohydrine to prepare a series of di- and tetraglycidyl epoxy resins with different molecular weights. P-Phenylene diamine and diaminodiphenylether were used as curing agents. The curing reactions and thermal properties of cured aromatic epoxy resins were investigated. Curing and post cure peaks were observed in dynamic DSC thermograms. The crosslinked network was thermally stable up to 470oC. Preliminary tests indicate that the resins exhibit superior adhesion properties.

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Sprenger, Stephan. "Nanosilica-Toughened Epoxy Resins." Polymers 12, no. 8 (August 8, 2020): 1777. http://dx.doi.org/10.3390/polym12081777.

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Surface-modified silica nanoparticles are available as concentrates in epoxy resins in industrial quantities for nearly 20 years. Meanwhile, they are used in many epoxy resin formulations for various applications like fiber-reinforced composites, adhesives or electronic components; even in space vehicles like satellites. Some of the drawbacks of “classic” epoxy toughening using elastomers as a second phase, like lower modulus or a loss in strength can be compensated by using nanosilica together with such tougheners. Apparently, there exists a synergy as toughness and fatigue performance are increased significantly. This work intends to provide an overview regarding the possibilities of nanotoughening with silica, the industrial applications of such epoxy resin formulations and the most recent research results.

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Liang, Bing, Tie Zhu Bao, Jun Cao, and Xiao Dong Hong. "Preparation and Properties of Halogen-Free Flame Retardant Epoxy Resins with Aryl Phosphinate Dianhydride Hardener." Advanced Materials Research 328-330 (September 2011): 1335–38. http://dx.doi.org/10.4028/www.scientific.net/amr.328-330.1335.

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Two halogen-free flame retardant epoxy resins were prepared by diglycidyl ether of bisphenol A (DGEBA) epoxy with two compound hardeners. The aryl phosphinate dianhydride BPAODOPE was used as a hardener and flame retardant when coupled with two curing agents, such as methylhexahydrophthalic anhydride (MeHHPA) and maleic anhydride (MA). The effect of the BPAODOPE contents on the fire resistance, thermal properties and mechanical properties of halogen-free flame-retardant epoxy resins were investigated in detail. The results showed that the phosphorus-containing epoxy resin composites had a higher UL-94 grade and char yield, furthermore, the flame retardation and the char yield of the cured epoxy resins increased with an increase of the phosphorus content, the phosphorus content of 1.75% was enough to achieve UL-94 V-1 grade and the best combination properties for the two composites with different hardeners.

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Wang, Fuzhong, and Lawrence Drzal. "Development of Stiff, Tough and Conductive Composites by the Addition of Graphene Nanoplatelets to Polyethersulfone/Epoxy Composites." Materials 11, no. 11 (October 30, 2018): 2137. http://dx.doi.org/10.3390/ma11112137.

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In this study, polyethersulfone (PES) was blended into epoxy resins to improve the fracture toughness of the epoxy resin without loss of mechanical properties, and then two grades of pristine graphene nanoplatelets (GnPs) were separately introduced into the PES/epoxy system to fabricate thermally conductive GnPs/PES/epoxy composites with high toughness as well as high stiffness. It was observed that the addition of GnPs obviously affected the final phase morphology by suppressing the phase separation process of the PES modified epoxy due to the increased viscosity and cure-reaction rate of PES/epoxy. The GnPs with a larger lateral dimension revealed a greater reinforcing effect, and the inclusion of 3 wt % GnPs (~5 μm in diameter) endowed the PES/epoxy matrix with a good thermal conductivity and improved the tensile, flexural, and storage modulus by 27.1%, 17.5%, and 15.6% (at 30 °С), respectively. Meanwhile, the fracture toughness was further enhanced by about 29.5% relative to the PES modified epoxy at the same GnPs concentration. The positive results suggest that the modification of epoxy resins using the PES and GnPs is an attractive approach for fabricating tougher and stiffer epoxy-based nanocomposites with multifunctional properties, which could widen the industrial applications of the epoxy resins.

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Kobayashi, Masahiko, Kyoko Tukamoto, and Bunichiro Tomita. "Application of Liquefied Wood to a New Resin System—Synthesis and Properties of Liquefied Wood/Epoxy Resins." Holzforschung 54, no. 1 (January 28, 2000): 93–97. http://dx.doi.org/10.1515/hf.2000.014.

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Summary A new resin system was developed by reacting liquefied wood with various epoxy compounds. Examination of the optimum conditions for the synthesis of the resins, and the behavior of liquefied wood in the cured resins were undertaken. Generally, the compatibility and film forming performance of liquefied wood/epoxy resins became better as the wood content increased. The presence of only one broad dispersion peak, due to the glass transition, was observed during dynamic mechanical measurement of resin films suggesting that the different components of the resin were compatible. The glass transition temperature of the cured resins could be modified by changing the kinds of epoxy compounds and the wood contents of liquefied wood. The presence of rubber elasticity at higher temperatures suggests that the resin systems consisted of cross-linking polymer networks.

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Kalali, Ehsan Naderi, Xin Wang, and De-Yi Wang. "Functionalized layered double hydroxide-based epoxy nanocomposites with improved flame retardancy and mechanical properties." Journal of Materials Chemistry A 3, no. 13 (2015): 6819–26. http://dx.doi.org/10.1039/c5ta00010f.

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Aiming at developing highly efficient nano fire retardants and fire retarding epoxy resins, a series of functionalized layered double hydroxides (LDHs) based on a multi-modifier system have been developed. These functionalized LDHs were used as novel nano flame-retardants for bisphenol epoxy resins and compared with unmodified LDHs.

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Das, Abhishek, and Gautam Sarkhel. "Effect of stoichiometric ratios for synthesized epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties." Pigment & Resin Technology 45, no. 4 (July 4, 2016): 265–79. http://dx.doi.org/10.1108/prt-08-2014-0060.

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Purpose The purpose of this paper is to study the effect of various stoichiometric ratios for synthesised epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties. Design/methodology/approach In the present study, EPN (EPN-1, EPN-2, EPN-3, EPN-4 and EPN-5) resins were synthesised by varying five types of different stoichiometric ratios for phenol/formaldehyde along with the corresponding molar ratios for novolac/epichlorohydrin. Their different physicochemical properties of interest, thermomechanical properties as well as morphological properties were studied by means of cured samples with the variation of its stoichiometric ratios. Findings The average functionality and reactivity of EPN resin can be controlled by controlling epoxy equivalence as well as cross-linking density upon its curing as all of these factors are internally correlated with each other. Research limitations/implications Epoxy resins are characterised by a three-membered ring known as the epoxy or oxirane group. The capability of the epoxy ring to react with a variety of substrates imparts versatility to the resin. However, these resins have a major drawback of low toughness, and they are also very brittle, which limits their application in products that require high impact and fracture strength. Practical implications Epoxy resins have been widely used as high-performance adhesives and matrix resins for composites because of their outstanding mechanical and thermal properties. Because of their highly cross-linked structure, the epoxy resin disables segmental movement, making them hard, and it is also notch sensitive, having very low fracture energy. Social implications Epoxy resin is widely used in industry as protective coatings and for structural applications, such as laminates and composites, tooling, moulding, casting, bonding and adhesives. Originality/value Systematic study has been done for the first time, as no exact quantitative stoichiometric data for the synthesis of EPN resin were available on the changes of its different properties. Thus, an optimised stoichiometric composition for the synthesis of the EPN resin was found.

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Vyhnánková, Michaela, Jakub Hodul, and Jiří Bydžovský. "Epoxy Resin Coatings Crystallization and Influence of Crystallinity on Shore Hardness and Tensile Properties." Solid State Phenomena 276 (June 2018): 173–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.276.173.

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The epoxy resins are very popular and plentifully used synthetic resins. The bisphenol A-based (DGEBA) and bisphenol F-based epoxy resins (DGEBF) crystallization is phenomenon which is for that kind of resins natural. They are undercooled liquids and they tend to form the crystal structure at the ambient temperature. The subject of the research is to determine the effect of some crystallinity of DGEBF on chosen mechanical parameters. The degree of crystallinity was counted through the specific weights of crystallized bisphenol F-based epoxy resins. The prepared crystallized samples of DGEBA/DGEBF mixtures were mixed in appropriate weight ratio with isophorondiamine (IPD) based curing agent. Measured was hardness Shore D according to EN ISO 868 standard and tensile parameters according to EN ISO 527-1 standard. Furthermore, the effect of crystallinity on chosen mechanical parameters was observed. It was found out that with the higher crystallinity maximum tensile stress and hardness increased close to the standard parameters amorphous DGEBA and DGEBF.

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Starovoitova, Irina, and Rustem Nizamiev. "Epoxy and epoxy novolac adhesive binders for structural reinforcement systems of building structures." E3S Web of Conferences 274 (2021): 04012. http://dx.doi.org/10.1051/e3sconf/202127404012.

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Today, along with the conventional materials and technologies for reinforcement of building structures, structural reinforcement systems based on polymer composites are on the rise. A structural reinforcement system consists of reinforcing filler (normally, carbon fiber fabric or cloth) and adhesive binder. This paper investigated the modification of epoxy nobake adhesive binders to provide a higher thermal resistance and mechanical strength. The influence of epoxy novolac resins on the processing and physical mechanical properties of adhesives, thermal resistance is studied. It is found that the substitution of 20-40 % of epoxy resin for epoxy novolac resin in the binder increases tensile strength by 40-50 %, flexural modulus by 20 %, reduces tensile strain, and increases glass transition temperature. From the processing point of view, it is more reasonable to use liquid epoxy novolac resins with a functionality of f=2.5 than semisolid resins with a functionality of f=3.6.

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Arcos Casarrubias, JA, A. Reyes-Mayer, R. Guardian-Tapia, P. Castillo-Ocampo, and A. Romo-Uribe. "Rubber Nanodomains Reinforced Epoxy Resin." MRS Advances 1, no. 21 (2016): 1571–76. http://dx.doi.org/10.1557/adv.2016.297.

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ABSTRACTIt has been reported that the addition of liquid rubbers, like poly(dimethylsiloxane) (PDMS), to epoxy resins alter the final morphology, increase the toughness and influence the curing kinetics. Due to immiscibility, there is phase separation of the elastomeric phase during curing giving rise to microdomains embedded in the epoxic matrix. The resultant heterogeneous morphology obtained after the reaction controls to an important extent the properties of the epoxy composite. Here we report a method to obtain well-dispersed rubber nanodomains of silyl-diglycidyl ether terminated polydimethyl siloxane (PDMS-DGE) in diglycidyl ether of bisphenol-A (DGEBA) epoxy by using a prepolymerization step. Light scattering and optical microscopy showed that initial mixing of pre-polymerized rubber produced phase separation with micron-scale droplet formation. However, as the curing reaction proceeded, the rubber domains decreased below optical resolution, light scattering intensity reached a maximum and then decreased. Finally, rubber nanodomains of about 100 nm size were formed at the end of curing reaction, as revealed by transmission electron microscopy (TEM). The pre-polymerization step induced a two-fold increase in gel time, tgel, due to lesser active groups available for reaction. Strikingly, tensile modulus and toughness increased, suggesting rubber-epoxy interaction. The final nanocomposite also exhibited higher thermal stability and char formation.

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Yang, Li, Miao Yin, Xiu Yun Li, and Han Bing Ma. "Thermal and Dielectric Properties of Inorganic-Organic Nanocomposites Involving Epoxy Resin and Polyhedral Oligomeric Silsesquioxanes." Advanced Materials Research 476-478 (February 2012): 665–69. http://dx.doi.org/10.4028/www.scientific.net/amr.476-478.665.

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In this paper, a type of nanoporous polyhedral oligomeric silisesquioxanes (POSS) containing eight functional groups have been synthesized and mixed with diglycidyl ether of bisphenol A (DGEBA) to form epoxy resin networks with nanostructures. The cured octa(aminophenyl) silsesquioxane (1c-POSS) and DGEBA system inherently possesses higher thermal stability and higher char yield than the control epoxy resins. Furthermore, the dielectric constant of the 1c-POSS/DGEBA material (4.36) is substantially lower than that of the neat epoxy resins (4.64) as a consequence the presence of nanoporous POSS cubes in the epoxy matrix.

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Li, Cheng, Jintao Wan, Ehsan Naderi Kalali, Hong Fan, and De-Yi Wang. "Synthesis and characterization of functional eugenol derivative based layered double hydroxide and its use as a nanoflame-retardant in epoxy resin." Journal of Materials Chemistry A 3, no. 7 (2015): 3471–79. http://dx.doi.org/10.1039/c4ta05740f.

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Aiming to develop a multi-functional flame retardant for epoxy resins, a novel bio-based eugenol derivative (SIEPDP) was synthesized, and was used to modify Mg–Al layered double hydroxide (SIEPDP-LDH). This modified SIEPDP-LDH was used as a novel nanoflame-retardant for bisphenol epoxy resins and compared with unmodified pristine LDH.

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Bratychak, Michael, Bogdana Bashta, Olena Astakhova, Olena Shyshchak, and Olha Zubal. "Synthesis Mechanism and Properties of Epoxy Resins Modified with Adipic Acid." Chemistry & Chemical Technology 13, no. 1 (March 5, 2019): 52–58. http://dx.doi.org/10.23939/chcht13.01.052.

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Eliaz, Noam, Eliora Ron, Michael Gozin, Sara Younger, Dvora Biran, and Noam Tal. "Microbial Degradation of Epoxy." Materials 11, no. 11 (October 29, 2018): 2123. http://dx.doi.org/10.3390/ma11112123.

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Epoxy resins have a wide range of applications, including in corrosion protection of metals, electronics, structural adhesives, and composites. The consumption of epoxy resins is predicted to keep growing in the coming years. Unfortunately, thermoset resins cannot be recycled, and are typically not biodegradable. Hence, they pose environmental pollution risk. Here, we report degradation of epoxy resin by two bacteria that are capable of using epoxy resin as a sole carbon source. These bacteria were isolated from soil samples collected from areas around an epoxy and polyurethanes manufacturing plant. Using an array of molecular, biochemical, analytical, and microscopic techniques, they were identified as Rhodococcus rhodochrous and Ochrobactrum anthropi. As epoxy was the only carbon source available for these bacteria, their measured growth rate reflected their ability to degrade epoxy resin. Bacterial growth took place only when the two bacteria were grown together, indicating a synergistic effect. The surface morphology of the epoxy droplets changed significantly due to the biodegradation process. The metabolic pathway of epoxy by these two microbes was investigated by liquid chromatography mass spectrometry. Bisphenol A, 3,3′-((propane-2,2-diylbis(4,1-phenylene))bis(oxy))bis(propane-1,2-diol) and some other constituents were identified as being consumed by the bacteria.

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Journal articles on the topic 'Resinas epoxi'

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