水工环氧材料断裂韧性的温度相关性研究

本文研究了一种特殊增韧剂对水工环氧材料低温韧性的影响,通过测试不同增韧剂用量体系在20℃~-40℃的断裂韧性KIC,对断裂韧性与温度的相关性进行了研究和分析。试验表明,非增韧环氧体系断裂韧性在低温下大幅降低,添加20~50份的增韧剂的环氧体系在常温下的断裂韧性较低,而低温韧性大幅提高,试验同时显示KIC与弹性模量密切相关,另外增韧剂提高了断裂面的外延形变,有利于提高低温韧性。从应用角度看,特殊增韧剂的加入在提高环氧材料低温断裂韧性的同时,适当降低了材料的弹性模量,有利于减少温度应力的积累,是提高低温条件下环氧抗裂性的理想途径。

Study on the relationship between fracture toughness and temperature of epoxy resin

The fracture toughness K1c 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 K1c and the temperature was discussed in this paper. It was found that K1c 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 K1c 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.