复合微胶囊填充型环氧树脂自修复复合材料的老化性能

采用浇注成型法制备新型环氧树脂-脲醛树脂@2-甲基咪唑复合微胶囊(E-51-UF@2-MI复合微胶囊)/环氧树脂自修复复合材料,研究湿热老化(65℃去离子水)、化学腐蚀(40%硫酸溶液、40%氢氧化钠溶液)、395 nm紫外线老化对新型自修复复合材料拉伸强度、弯曲强度和自修复性能的影响。结果表明,新型自修复复合材料在65℃去离子水中浸泡8 h后,吸湿率达到稳定状态,最大吸湿率为0.15%;在40%硫酸溶液中浸泡4 d,拉伸强度和弯曲强度最小损失率分别为25.7%和21.6%;在40%氢氧化钠溶液中浸泡5 d,拉伸强度和弯曲强度最小损失率分别为22.5%和19.8%;经紫外线老化4 d,拉伸强度和弯曲强度最小损失率分别为26.1%和46.1%;在40%硫酸溶液和395 nm紫外线老化条件下,修复率呈现下降趋势,而在40%氢氧化钠溶液腐蚀条件下,其修复率先略有上升后不断下降。自修复性能下降原因在于:基体老化、微胶囊老化,以及微胶囊与基体的脱离。

Aging Properties of Microcapsule-Filled Epoxy Resin Self-Healing Composites

Few researches on aging properties of self-healing composites filled with microcapsules have been made.The new composites of epoxy resin-urea-formaldehyde resin@2-methylimidazole composite microcapsules(E-51-UF@2-MI composite microcapsules)/epoxy resin self-healing composites by casting method were prepared.The effects of hydrothermal aging(deionized water at 65℃),chemical corrosion(40% sulfuric acid solution,40%sodium hydroxide solution),or ultraviolet aging at 395nm on the tensile strength,flexural strength and self-healing properties of new self-healing composites were studied.The results show that the moisture absorption ratio of the new self-healing composites reaches a stable state after being immersed in deionized water at 65℃ for 8h,and the maximum moisture absorption ratio is 0.15%,indicating that the materials have good water resistance;the new self-healing composites were immersed in 40% sulfuric acid solution for 4d,and the tensile strength and bending strength reach the minimum loss ratios of 25.7% and 21.6%,respectively;the new self-healing composites were immersed in 40% sodium hydroxide solution for 5d,and the tensile strength and bending strength reach the minimum loss ratios,which are 22.5% and 19.8%,respectively;the new self-healing composites were irradiated with ultraviolet light for 4d,and the tensile strength and bending strength reach the minimum loss ratios of 26.1% and 46.1%,respectively;under 40%sulfuric acid solution corrosion and 395nm ultraviolet aging conditions,the selfhealing ratios of the new self-healing composites show a downward trend,while under 40% sodium hydroxide solution corrosion condition,the self-healing ratios increase slightly at first and then decrease continuously.