ZHAO Bo, LI Jing-wei, LU Yi-hui, QU Yang (Department of structure and materials, IWHR, Key Laboratory of Hydraulic Engineering Construction and Safety of MWR, Beijing 100038, China)

Abstract: The fracture toughness KIC at the temperature of 20℃ to -40℃ of some epoxy resin formulae toughened by a kind of impact modifier has been investigated, and the relationship between KIC and the temperature was discussed in this paper. It was found that KIC of pure epoxy resin reduced greatly along with the temperature decreasing, but it improved at lower temperature when the 20~50 portion impact modifier was added. Meanwhile the modulus test results indicated that KIC is related tightly with modulus. The additive of impact modifier to epoxy can enlarged the deformation of the fracture section, and it's an ideal way to resist cracking of epoxy at low temperature due to the role of increasing for fracture toughness and reducing for modulus, which can decrease the temperature stress in the process of temperature decreasing.

Key words: Epoxy resin, Fracture toughness, toughening, low temperature

Published in: Journal of China Institute of Water Resources and Hydropower Research (Vol. 10 No. 2, 2012)