Effect of Aqueous HCl with Dissolved Chlorine on Certain Corrosion-Resistant Polymers

Polypropylene, poly­(ethylene terephthalate), ethylene chloro tetrafluoroethylene, ethylene tetrafluoroethylene, and epoxy vinyl ester resin (Derakane 470-300) were evaluated in aqueous HCl containing chlorine gas at high temperature as a corrosion media. Fourier transform infrared, X-ray diffraction, energy-dispersive X-ray, and dynamic mechanical analyzer are used for identification of nature of chemical reactions on polymer chain. Puncture resistance and hardness tests were done to evaluate the mechanical strength after the exposure. The scanning electron microscopy image was taken to check the morphological change of polymer surface. Chlorination and oxidation reactions were observed to be responsible for the stability behavior of polymer. A mechanism proposed for both chlorination and oxidation on polymer.