In this study, the influence of hydrogen chloride (HCl) gas and water vapor contained in HCl gas on the chemical and mechanical properties of polyphenylene sulfide (PPS) filter media at a high-temperature of 200°C were investigated. Exposures to HCl gas, with or without water vapor, hardly changed the elemental composition and elemental ratios of the PPS fibers, nor induced any chemical structural changes. In contrast, the crystallinity of PPS fibers slightly increased by exposure to HCl gas, whereas this increase in the crystallinity was suppressed in the presence of water vapor. Consequently, PPS filter media exposed to HCl gas provided consistently lower elastic modulus and tensile strength than those exposed to HCl gas with water vapor. These results indicate that PPS filter media exhibit a high chemical durability against HCl gas and that with water vapor at high temperature, and that which is comparable to against inert gas atmospheres.
Fujiwara et al. (Tue,) studied this question.