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目的：制备碳纳米管复合水性丙烯酸涂层,探索分析碳纳米管含量对涂层力学和防腐性能的影响规律。方法采用高速球磨方式制备3％,1％,0.5％三种含量(以质量分数计)的碳纳米管复合涂层,对涂层附着力、耐冲击性、耐弯曲性等力学性能进行测试,以电化学阻抗技术来评价碳纳米管复合涂层的防腐性能。结果添加碳纳米管显著提高了涂层的附着力,并且随着碳纳米管含量的增加,附着力上升；其他力学性能,如耐冲击性、耐弯曲性,在不同含量下均保持良好。对改性和未改性的涂层进行了电化学阻抗测试,其中1％的碳纳米管涂层电化学性能最优,在浸泡36 h后,未改性涂层低频区阻抗模值|Z|0.01为2.5×103Ω·cm2,0.5％的碳纳米管涂层为1.1×106Ω·cm2,1％的为1.4×108Ω·cm2,3％的为7×102Ω·cm2。结论由于碳纳米管本身的纳米效应,在较低含量时即可提高涂层的性能,并存在最优含量,超过此含量后性能有所下降。

ABSTRACT:Objective To develop an acrylic-based waterborne coating system by using MWCNT as the additive and examine the effect of the carbon nanotube content on the mechanical property and corrosion resistance of the coating. Methods The MWCNTs were dispersed in the acrylic resin by high-speed ball-milling. And acrylic composite coatings containing 0, 0. 5, 1, 3wt% MWC-NT were prepared. The mechanical property and corrosion resistance of the coatings were evaluated using mechanical tests such as adhesion, impact resistance, bending resistance, and electrochemical impedance spectroscopy (EIS). Results The addition of car-bon nanotubes obviously increased the adhesion of the coating, and the adhesion increased with increasing MWCNT content in the acrylic composite coatings, and there was no loss in other mechanical properties such as impact resistance and bending resistance at different MWCNT contents. Electrochemical impedance tests on the modified and unmodified coatings revealed that the coating con-
taining 1% carbon nanotubes had the best electrochemical property. After 36 h immersion in 3. 5 wt% NaCl, the total impedance magnitude (|Z|) at 0. 01 Hz of acrylic coating and 0. 5%, 1%, 3% composite coating was 2. 5×103 Ω·cm2, 1. 1×106 Ω· cm2, 1. 4×108 Ω·cm2 and 7×102 Ω·cm2, respectively. Conclusion Due to the nano effect of the carbon nanotubes, the per-formance of the coating could be improved by low content of carbon nanotubes, but there was an optimal content, if the content ex-ceeded this value the performance would decrease.