Oxidation degradation of polyphenylene sulfide needle felt at different sulfuric acid dew point temperatures

Sulfuric acid dew point is an important parameter in coal-fired power plants as it affects many equipments, materials, and pipes, including filter bags. This article puts forward a new method to test the effect of different sulfuric acid dew points on the performance of polyphenylene sulfide (PPS) needle felt. Oxidation reaction mechanisms were predicted using Fourier transform infrared analysis. The results show that the degradation starts with S atoms in the PPS molecular chain; first, the thioether bond is broken, followed by sulfonation of benzene, and finally concluding with the carbonization of PPS. Furthermore, PPS thermal properties also show a decrease in the melting temperatures and thermal decomposition temperatures as well as an increase in the residual mass of the initial weight with increasing sulfuric acid dew point. Changes in the thermal properties of PPS further confirmed that different reaction mechanisms exist under different acid dew points.