【作者】 张驰；

【导师】 李澄；

【作者基本信息】 南京航空航天大学 ， 物理化学， 2010， 硕士

【摘要】 为了评价低红外发射率涂层的防腐蚀性能,估计其使用周期,本文采用塔菲尔极化曲线（Tafel）、电化学阻抗谱（EIS）两种电化学方法,结合浸泡试验研究以聚氨酯为粘合剂,铜粉、硅烷偶联剂改性铜粉、丙烯酸改性铜粉为填料的聚氨酯基低红外发射率涂料、以环氧改性聚氨酯为粘合剂,铜粉、硅烷偶联剂改性铜粉、丙烯酸改性铜粉为填料的环氧改性聚氨酯基低红外发射率涂料以及以三元乙丙橡胶（EPDM）、马来酸酐改性三元乙丙橡胶（EPDM-g-MAH）为粘合剂、铜粉为填料的三个系列的低红外发射率涂料在模拟海水环境（3.5wt.% NaCl溶液）下的电化学腐蚀行为,并借助开路电位( E_ocp)、腐蚀电流密度( i_corr)、涂层电阻( R_coat)、涂层电容( C_coat)、涂层特征频率（ f_b）来分析评价同一体系涂层的防腐蚀性能。结果表明:聚氨酯基低红外发射率涂层,在浸泡初期,改性涂料表现出较好的防腐蚀性能,但随着浸泡时间延长改性涂料失效速率加快,在整个浸泡过程中未改性涂料的防腐蚀性能最好。但在长期浸泡过程中,亲水基团-COOH、-OC₂H₅的存在促进了水的渗入,加速了改性涂层的失效。环氧改性聚氨酯基低红外发射率涂层,在浸泡初期,以铜粉为填料的涂层表现出较好的防腐蚀性能,但随着浸泡时间延长其失效速率加快,在整个浸泡过程中防腐蚀性能最差。而经过丙烯酸改性铜粉为填料和经过硅烷偶联剂改性铜粉为填料的涂层在浸泡过程中表现出较好的防腐蚀性能。铜粉填充三元乙丙橡胶基和铜粉填充马来酸酐改性三元乙丙橡胶基的低红外发射率涂料,在浸泡初期在较短的时间内腐蚀介质均能渗入两种涂层内部,涂层表现出较弱的防护性能。更多还原

【Abstract】 To review the corrosion-resistance properties of low infrared emissivity coatings and predict their lifetime, electrochemical measurement techniques including polarization curves （Tafel） and electrochemical impedance spectroscopy （EIS） techniques were employed to investigate the electrochemical corrosion behavior of three different series of low infrared emissivity coatings in simulated sea water（3.5 wt.% NaCl aq. solution）. The coating series concernd includes polyurethane-based and EP modified PU-based coatings in which were filled with Cu powder, Cu powder modified by silane coupling agent , and Cu powder modified by acrylic acid respectively. EPDM and EPDM-g-MAH-based coatings filled with Cu powder were also investigated in detail. The corrosion-resistance properties of coatings were evaluated and concluded by comparing Eocp, Rcoat , Ccoat ,icorr and fb , of the samples under same conditions.The results show that at the initial stage of immersion, both polyurethane-based coatings filed with modified Cu powder behave a better corrosion-resistance. The degeneration of protection of the coatings to the substrate, however, begins to accelerate with the immersion time going on. As a comparision, the coating filed with unmodified Cu powder shows a much better protection ability. With the immersion time going on, water permeats through the coatings and causes a possible failure of protection and the process may accelerate due to the presence of hydrophilic groups, such as -COOH and -OC₂H₅ .For the series of EP modified PU-based low infrared emissivity coatings, the coating filled with Cu powder show a better protection to the substrates at the initial stage of immersion. With the time of immersion going on, the rate of protection failure tend to accelerate. It exhibits the the worst for its protection ability. But the coatings filled with acrylic acid and silane coupling agent modified Cu powder exhibit a much better corrosion-resistance ability.Cu powder filling EPDM and EPDM-g-MAH-based coatings can not prevent the penetration of corrosive species through the coatings effectively and, as a result, coatings become failure in a short time and lead to a poor protection ability.更多还原