title: Comparative electrochemical studies at different operational temperatures for the effect of nanoclay platelets on the anticorrosion efficiency of organo-soluble polyimide/clay nanocomposite coatings.
abstract: 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).
authors.affiliation: Department of Chemistry, Center for Nanotechnology at CYCU and R & D Center for Membrane Technology, Chung-Yuan Christian University, Chung Li 32023, Taiwan, ROC.
authors.forename: Kung-Chin
authors.initials: KC
authors.lastname: Chang
authors.forename: Hsin-Hua
authors.initials: HH
authors.lastname: Huang
authors.forename: Mei-Chun
authors.initials: MC
authors.lastname: Lai
authors.forename: Chih-Bing
authors.initials: CB
authors.lastname: Hung
authors.forename: Brojogopal
authors.initials: B
authors.lastname: Chand
authors.forename: Jui-Ming
authors.initials: JM
authors.lastname: Yeh
authors.forename: Yuan-Hsiang
authors.initials: YH
authors.lastname: Yu