Polyphenylene sulfide resins

The macromolecule of polyphenylene sulfide (PPS) consists of the basic monomer of parasubstituted benzene rings [—C6 H5 —S—]n. The high crystallinity and thermal stability of the chemical bond existing between the aromatic ring and the sulfur atom are responsible for the high melting point, thermal stability, inherent flame-retardance, and good chemical resistance of polyphenylene sulfide. There are no known solvents of polyphenylene sulfide below 205°C. Chemical resistance is outstanding and the temperature usefulness ranges from –170°C to 190°C. Coatings prepared from the resin are available. Considerable strength with high elastic modulus can be obtained by the addition of glass or other mineral fillers to the material.

Polyphenylene sulfide (PPS) is a crystalline, high-performance engineering thermoplastic characterized by outstanding high-temperature stability, inherent flame resistance, and broad chemical resistance. PPS resins and compounds manufactured in the United States are tradenamed Ryton.
A wide range of injection-molding grades of PPS is available. The series with various glass-fiber levels (designated R-3, R-4, and R- 5) is recommended for mechanical electronic applications requiring high mechanical strength, impact resistance, and insulating characteristics. All other compounds contain various mineral fillers in addition to glass-fiber reinforcement. Ryton R-7 and R-8 are suitable for electrical applications requiring high arc resistance and low arc tracking. The R-10 series of pigmented compounds includes several grades suitable for support of current-carrying parts in electrical components. PPS is essentially transparent to microwave radiation, so the R-11 series is suited specifically for microwave ovenware and appliance components.
Unreinforced PPS resins are also available as powders for slurry coating and electrostatic spraying. The resin coatings are suitable for food-contact applications as well as for chemical- processing equipment.