Degradation of poly(1,4-phenylene sulfide) on exposure to chlorinated water

摘要

Experiments were performed to characterize events pertinent to the degradation of poly(1,4-phenylene sulfide) upon exposure to chlorinated water. Studies were specifically undertaken to identify the reactive species involved in the degradation reactions. Species of concern are Cl_2, HOCl, and singlet molecular oxygen, O_2(a~1Δ_g), all of which exist in chlorinated water and whose concentration profiles are pH-dependent. Polymer degradation was monitored in pH-dependent experiments using FTIR spectroscopy. Data obtained indicate that Cl_2 and HOCl are the principal reactive species that initiate degradation, and that the pertinent reactions occur over the pH range of ～2—8. Reaction products include not just the sulfoxide and sulfone, but species derived from the chlorination of the aromatic ring and subsequent ring oxidation. Spatially-resolved FTIR mapping experiments illustrate how the progress of the reactions depends on the diffusion of reactive species from the surface of a given sample into the bulk. These results are important with respect to the development of polymers that can better resist exposure to water that has been chlorinated to kill bacteria.