PPS (polyphenylene sulphide) is a high-performance engineering plastic with excellent resistance to many solvents, fuels, oils and chemical solutions. Its main advantage is that it can retain useful properties in demanding chemical environments, including at elevated temperatures. However, strong acids, oxidising agents and some amines can damage it.
Chemical resistance describes how well a material withstands exposure without swelling, softening, cracking or losing strength. For polymer fasteners and components, this matters because a part can appear intact while its ability to carry a load has deteriorated.
How PPS compares with other engineering plastics
The following gives a general comparison; suitability still depends on the specific chemical and operating conditions.
| Polymer | Comparison with PPS |
| PEEK | Both offer broad chemical resistance, including resistance to many solvents and alkalis. Neither is universally superior: the exact chemical, concentration, and temperature determine the better choice. |
| POM / Acetal | POM performs well with many fuels, oils, and alcohols, but has greater limitations with acids. PPS generally provides a broader option for aggressive chemical exposure. |
| PA / Nylon | Nylon has useful resistance to many oils and fuels, but acids can attack it. PPS is generally a stronger candidate where acid exposure is a concern. |
| PC | PC is more vulnerable to many organic solvents, including ketones, which can cause cracking or damage. PPS generally offers much broader solvent resistance. |
| PEI | PEI has useful chemical resistance, but has limitations with ketones and strong alkalis. PPS generally performs better in these chemical groups. |
| PP |
PP already resists many acids and alkalis well. PPS does not automatically offer better chemical compatibility; the full service conditions must justify the choice. |
Where PPS has limitations
PPS should not be described as resistant to every chemical. Strong oxidising environments, certain strong acids and some amines require particular attention. Temperature can also change the result substantially: PPS GF40 grade has little tensile-strength change after exposure to 10% hydrochloric acid at 23°C, but significant deterioration at 80°C under the stated test conditions.
Does glass reinforcement improve chemical resistance?
PPS GF40 is not automatically more chemically resistant than unfilled PPS. Glass reinforcement changes mechanical performance, but the fibres and the bond between the fibres and polymer introduce additional considerations. Strong alkalis can affect glass-reinforced grades, while prolonged hot-water exposure can reduce strength at the glass–polymer interface. For a PPS screw, nut, washer or machined component, selection should therefore consider:
- The exact chemical or mixture and its concentration.
- Operating temperature and exposure duration.
- Whether contact is occasional splashing or continuous immersion.
- The precise PPS grade and reinforcement.
- Mechanical stress, including tightening force and sustained loading.
PPS is a strong candidate when broad chemical resistance is needed, but compatibility should be checked for the finished component under its actual working conditions.