The chemical resistance of Ryton® PPS is well known to be outstanding, even at elevated temperatures. However, being an organic polymer, it can be affected by some chemicals under certain conditions. Over the past twenty-five years, we have accumulated a large database on exposure of Ryton® PPS to a wide variety of chemicals. Although it is not possible to test every chemical, we have seen that chemicals having similar structures and/or properties tend to have similar effects on Ryton® PPS compounds. Therefore, we are able to provide some general recommendations about the compatibility of Ryton® PPS injection molding compounds with entire classes of chemicals.
The various grades of Ryton® PPS injection molding compounds differ primarily in the combination of fillers used and/or the molecular weight and/or molecular architecture of the PPS polymer used. There are also various combinations of minor additives in the different compounds. These variations can have a very significant effect on the mechanical properties of the different compounds. However, regardless of molecular weight and/or molecular architecture, the PPS polymer is just as resistant to chemical attack, and there are but a few key aspects of chemical resistance that are affected by fillers and additives. Acids may have a more detrimental effect on compounds containing mineral fillers due to the susceptibility of the mineral fillers to acid digestion. Also, certain grades of Ryton® PPS compounds are specially formulated to be more resistant to the detrimental effect of high temperature water on the adhesion of the PPS polymer to the glass fiber reinforcement. With these exceptions, the chemical resistance properties of various Ryton® PPS compounds are quite similar.
This is intended to be a general guide to illustrate the degrees of chemical resistance one might expect Ryton® PPS compounds to exhibit when exposed to various chemicals. Performance will vary depending on particular chemicals used (or combinations thereof), particular conditions of service, and particular Ryton® PPS compounds used. Temperature and duration of exposure are critical factors that must be considered when determining the degree of chemical resistance required for a particular application. An insignificant effect that occurs over a short time, or at low temperature, may become significant in a few months or at elevated temperatures. It is important to consider which conditions and what properties are critical to an application, and then evaluate chemical resistance data relative not only to the performance requirements, but also relative to the performance of other materials used in the same application. If you require further information, our chemists can provide opinions about the suitability of Ryton® PPS for particular chemical environments, based on our knowledge of the chemistry of PPS and our compounds. However, testing under conditions as similar as possible to actual service conditions is always recommended as the best way to determine chemical compatibility for a particular application.
