Comparative electrochemical studies at different operational temperatures for the effect of nanoclay platelets on the anticorrosion efficiency of organo-soluble polyimide/clay nanocomposite coatings.
A organic soluble polyimide (SPI) prepared from 4,4'-Oxydianiline and 4,4'-(4,4'-Isopropylidenediphenoxy)bis(phthalic anhydride) was mixed with organo-modified montmorillonite (MMT) in N,N-Dimethylacetamide. The organic soluble polyimide-clay nanocomposite (PCN) materials were characterized by Fourier-Transformation infrared (FTIR), spectroscopy, wide-angle X-ray diffraction (WAXRD) patterns and transmission electron microscopy (TEM). It should be noted that the nanocomposite coating containing 3 wt% of clay loading was found to exhibit an observable enhanced corrosion protection on cold-rolled stell (CRS) electrode at higher operational temperature of 50 degrees C, which was even better than that of uncoated and electrode-coated with SPI alone at room temperature of 30 degrees C based on the electrochemical parameter evaluations. In this work, all electrochemical measurements were performed at a double-wall jacketed cell, covered with a glass plate, through which water was circulated from a thermostat to maintain a constant operational temperature of 30, 40 and 50 +/- 0.5 degrees C. Moreover, a series of electrochemical parameters shown in Tafel, Nyquist and Bode plots were all used to evaluate PCN coatings at three different operational temperatures in 5 wt% aqueous NaCl electrolyte. The molecular barrier properties at three different operational temperatures of SPI and PCN membranes were investigated by gas permeability analyzer (GPA) and vapor permeability analyzer (VPA).
Chang
Kung-Chin
KC
Department of Chemistry, Center for Nanotechnology at CYCU and R & D Center for Membrane Technology, Chung-Yuan Christian University, Chung Li 32023, Taiwan, ROC.
Huang
Hsin-Hua
HH
Lai
Mei-Chun
MC
Hung
Chih-Bing
CB
Chand
Brojogopal
B
Yeh
Jui-Ming
JM
Yu
Yuan-Hsiang
YH