活性γ型宫内节育器中消炎痛对铜与不锈钢电偶腐蚀的影响

EFFECT OF INDOMETHACIN ON GALVANIC CORROSION OF COPPER AND STAINLESS STEEL ON INTRAUTERINE DEVICE

针对活性γ型宫内节育器,研究了在pH6～8的生理盐水中消炎痛对铜与不锈钢的电偶腐蚀的影响。消炎痛不影响铜的自然腐蚀电位及其随溶液pH的升高而正移的规律;它使不锈钢的自然腐蚀电位略有正移,但不改变其随溶液pH的升高而负移的趋势。对于铜/不锈钢电偶,消炎嫡不改变铜的阳极行为,但使不锈钢的阴极极化曲线正移;添加消炎痛使电偶电流明显增大。不锈钢可能出现活化状态,这时如与铜偶合,铜就成为阴极,从而抑制铜的腐蚀。消炎痛虽使不锈钢的电位略有正移,但不改变它原来的钝化状态或活化状态。

7 -type active intrauterine device (IUD) is made of pure copper and stainless steel together with indomethacin for blood loss control. Galvanic corrosion behavior of the two dissimilar metals in the absence and presence of indomethacin were compared in physiological saline with pH 6-8. Indomethacin did not affect corrosion potential of copper, but caused stainless steel a slight potential shift towards positive. With increasing pH of the media, copper potential shifted towards positive, whereas stainless steel potential shifted towards negative. Indomethacin did not change these dependence. In the copper/stainless steel couple, copper acted as anode. Anodic polarization behaviour of copper was not altered by indomethacin, but its cathodic polarization curve was moved up. Indomethacin increased the galvanic current significantly. It was also noticed that stainless steel might be activated due to improper handling of the IUD. In this case, copper became cathode of the couple and its corrosion would be suppressed. Indomethacin did not turn the stainless steel from active state into passive state.