土酸介质中三聚磷酸钠对铝的缓蚀研究

Studies on Corrosion Inhibition of Pentasodium Triphosphate on Aluminum in Mud Acid

利用失重实验研究了土酸介质中三聚磷酸钠（STPP）对铝的缓蚀作用，并获得了相关热力学参数。结果表明：在5％的土酸介质中三聚磷酸钠对铝的腐蚀有良好的抑制作用。三聚磷酸钠在铝表面产生单分子层吸附，且满足朗格缪尔吸附规律。随着温度升高，吸附能力减弱，缓蚀效率下降。吸附过程是放热过程，熵值减小，自由能减小。

The corrosion inhibition efficacy of pentasodium triphosphate （STPP） for aluminum in mud acid solution were investigated by the weight loss method. The thermodynamics parameters of adsorption were determined. It was shown by the result that STPP could control the corrosion of aluminum in 5 % mud acid solution effectively. STPP inhibited corrosion of aluminum by monolayer adsorption on the aluminum surface. The rule of adsorption conforms with Langmuir＇s isotherm. The adsorption ability and corrosion inhibition efficiency were decreased with temperature increasing. The adsorption process is an exothermic process. The entropy and Gibbs free energy were decreases.