Estabelecimento de ciclo de cura de pré-impregnados aeronáuticos

• Autor(a) principal: Costa, Michelle L.
• Data de Publicação: 2005
• Outros Autores: Rezende, Mirabel C., Botelho, Edson C. [UNESP]
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1590/S0104-14282005000300014; http://hdl.handle.net/11449/211504
• topic: Cure cycle; prepreg; cure kinetics; thermal and rheological analyses; Ciclo de cura; pré-impregnado; cinética de cura; análises térmicas e reológicas

Autoclave molding produces polymer composites, where the processing conditions can be optimized with physicochemical knowledge of the polymeric matrix. The cure reaction evolves simultaneously with changes in rheology, which is normally refered to as rheo-kinetic behavior. With the knowledge of the appropriate cure cycle one can identify the steps in which pressure should be applied and when to raise the temperature. This paper is aimed at investigating the cure, kinetics and rheological parameters of three prepreg epoxy systems, namely F161, F584 and 8552, which are currently used in the Brazilian aeronautic industry. Differential scanning calorimetry (DSC) and rheological techniques have been used, both in the isothermal and dynamic modes. Kinetics data were obtained from dynamic and isothermal DSC, with rheological measurements being carried out during the cure. The mathematical models used were the nth order reaction model and the autocatalytic model with order of 2. The gel temperature was ~100 °C, and the corresponding gelification time was 135 s. With the determination of the kinetics for the cure and of the rheological parameters of the prepreg systems, a cure cycle should be established that led to high-performance composites using the autoclave molding.