Avaliação da temperatura de transição vítrea de compósitos poliméricos reparados de uso aeronáutico

Published on Mar 1, 2006in Polimeros-ciencia E Tecnologia1
· DOI :10.1590/S0104-14282006000100016
Jane Maria Faulstich de Paiva16
Estimated H-index: 16
Jane Maria Faulstich de Paiva9
Estimated H-index: 9
+ 1 AuthorsMirabel Cerqueira Rezende34
Estimated H-index: 34
This work shows the evaluation of the glass transition temperature (T g ) by DMTA of three different families of repaired polymeric composites, manufactured with carbon fiber fabric/epoxy F584, glass fabric/epoxy F161 and aramide fabric/epoxy F161, respectively. The composites were laminated by conventional hand lay-up process used in aeronautical industry. Afterwards, simulated damages, scarf type, were made and overlapping layers of F155 epoxy resin prepregs repaired them. The DMTA curves show the effects of combination of different systems resins on the T g values and, consequently, on the service temperature of the repaired laminate. The used repairing material (based on epoxy resin F155 and on epoxy adhesive film FM73) decreased the T g of the repaired laminates in approximately 30 °C for the carbon and glass laminates. The conditioning of aramide laminate under elevated humidity and temperature provoked a more decrease of the T g (reduction of approximately 40 °C). The T g reduction for the repaired laminates is attributed to the adhesive film migration into the F155 resin system during the cure process and also to the resin plasticization by water diffusion during the hygrothermal conditioning. The T g reduction leads to a decrease of the service temperature of the repaired polymeric composite.
ABSTRACT In this work, the thermal stability of different polymeric composite laminates used in the aeronautical field was investigated by thermogravimetric (TGA) and dynamic mechanical thermal (DMTA) analyses. Four different types of laminates manufactured by combining two epoxy resin systems (F584 and F155) and two different types of carbon fiber fabric reinforcements were examined. The mass losses of the laminates were evaluated by TGA and the glass transition temperatures (Tg) were determine...
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