薄层防锈油膜的透水和透氧行为

PERMEATION BEHAVIOUR OF WATER AND OXYGEN THROUGH THIN LAYER RUST PREVENTIVE OIL

本文利用吸油滤纸形成的薄层油膜开展了实验研究。研究结果表明,受试验的两种防锈油的透水和透氧行为与它们的基础油基本相同,同时,透过薄层防锈油的水和氧远远超过了通常条件下金属发生大气腐蚀时所需的数量。这说明防锈油不是依靠阻碍水和氧的扩散而起作用的。

There are two possible concepts on mechanism of inhibition of thin layer rust preventive oils (RPO). The first explanation is the chemisorption of inhibitors present in RPO on metallic substrate. Another is the lower permeability of water and oxygen through RPO. The main purpose of this work is to evaluate the contribution due to the second mechanism. For experimental investigation, the oil films were prepared by soaking filter paper with the oil under study. The permeability of the oil film to water was determined in terms of the weight loss of water from a container covered with oiled filter paper. Oxygen diffusion tests were conducted on the basis of the change of oxygen concentration in a chamber as a result of passage of oxygen through oil film measured by coulometric oxygen sensor. Two RPOs showing satisfactory rust prevention performance were tested. No difference is observed in water and oxygen permeation behaviour between the two RPOs and their uninhibited base oil. It means that the presence of thinhibitors in RPO has little effect on permeability. The data on water and oxygen permeation rate obtained also show that RPO films are so permeable to water and oxygen that they cannot inhibit corrosion by impeding diffusion of these two corrodents. It could be concluded that the inhibitive action of RPO is not dependent on the prevention of water and oxygen permeation.