INTERFACES OF POLYPHENYLENE SULFIDE-TO-METAL JOINTS

High-temperature polyphenylene sulphide (PPS) film was deposited on the surface of cold-rolled stainless and galvanized steels by slurry coating in N2 and O2 gases at 350-degrees-C The value of the interfacial PPS/steel bond strength depended primarily on the species of sulphur-related iron compounds formed as reaction products at the interfaces. The order of these reaction products, which play an important role in developing bond strength, was Fe2(SO4)3 > FeSO4 > FeS. In contrast, the conversion of ZnS formed at the PPS/galvanized steel interfaces, into ZnSO4 led to a catastrophic loss of bond strength.