Avaliação das Propriedades Termo-Mecânicas de Borracha Nitrílica após Ensaio de Compatibilidade de acordo com ASTM D 3455
Thermal - Mechanical Properties Evaluation of Nitrilic Rubber after Compatibility Test according to ASTM D 3455
Pinto, Carlos Eduardo da S.; Wasilkoski, Cleuza; Tomczak, Fábio; Oliveira, Suely M. de; Souza, Gabriel P. de; Meyer, Adailze L.
http://dx.doi.org/10.1590/S0104-14282006000300013
Polímeros: Ciência e Tecnologia, vol.16, n3, p.230-234, 2006
Resumo
O copolímero butadieno – acrilonitrila – NBR é comumente aplicado na confecção de gaxetas e anéis de vedação para transformadores elétricos isolados a óleo mineral. Durante o uso esses materiais permanecem em contato com óleo em temperaturas próximas a 90 ºC provocando alterações físicas e químicas no material elastomérico e no óleo. Neste trabalho, estudou-se a variação das propriedades mecânicas do elastômero resultantes do ensaio de compatibilidade (ASTM D 3455)[³]. A caracterização mecânica foi realizada por ensaios de resistência a tração, dureza e análise dinâmico-mecânica (DMA). A verificação da estabilidade térmica e a composição do NBR foram obtidas através de análise termogravimétrica (TGA).
Palavras-chave
Gaxetas - NBR, compatibilidade óleo mineral, ensaio mecânico
Abstract
The copolymer of acrylonitrile and butadiene - NBR is commonly used to manufacture gaskets and seals to be used in electrical transformers insulated by mineral oil. During operation those materials are constantly in contact with oil at temperatures that can reach 90 ºC, causing physical and chemicals changes in both gaskets and oil. In this paper the changes in elastomer mechanical properties after the compatibility test were studied (ASTM D 3455)[3]. This characterization was done by tension properties, hardness and dynamical mechanical analysis (DMA). The evaluation of thermal stability and composition of the NBR was carried out through thermogravimetry analysis (TG).
Keywords
NBR gaskets, mineral oil compatibility, mechanical tests
References
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