Polyphenylene sulfide (PPS) is an organic polymer consisting of aromatic rings linked with sulfides. Synthetic fiber and textiles derived from this polymer are known to resist chemical and thermal attack. PPS is used to make filter fabric for coal boilers, papermaking felts, electrical insulation, specialty membranes, gaskets, and packings. PPS is the precursor to a conducting polymer of the semi-flexible rod polymer family. The PPS, which is otherwise insulating, can be converted to the semiconducting form by oxidation or use of dopants.[1]
Polyphenylene sulfide is an engineering plastic, a high-performance thermoplastic.[2] PPS can be molded, extruded, or machined to high tolerances. In its pure solid form, it may be opaque white to light tan in color. Maximum service temperature is 218 °C (424 °F). PPS has not been found to dissolve in any solvent at temperatures below about 200 °C (392 °F).
ChevronPhillips manufactures the most common form in industry under the brand name Ryton.
An easy way to identify the plastic is by the metallic sound it makes when struck.
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PPS is one of the most important high temperature polymers because it exhibits a number of desirable properties. These properties include resistance to heat, acids and alkalies, and to mildew, to bleaches, aging, sunlight, and abrasion. It absorbs only small amounts of solvents and resists dyeing. PPS is an example of a Thermoplastic.
The Federal Trade Commission definition for sulfur fiber is "A manufactured fiber in which the fiber-forming substance is a long chain synthetic polysulfide in which at least 85% of the sulfide (—S—) linkages are attached directly to two (2) aromatic rings."
The PPS (polyphenylene sulfide) polymer is formed by reaction of sodium sulfide with p-dichlorobenzene:
The process for commercially producing PPS (Ryton) was developed by Dr. H. Wayne Hill Jr. and Mr. James T. Edmonds at Phillips Petroleum Company.[3] N-methylpyrrolidone is used as the reaction solvent since it is stable at the high temperatures required for the synthesis and it dissolves both the sulfiding agent and the oligomeric intermediates. The major challenge is controlling the degree of polymerization, which is in part controlled by managing the water content of the reaction mixture. The polymer is extruded by melt spinning to produce filament fibers.
The first U.S. Commercial Sulfur Fiber was produced in 1983 by Phillips Fibers Corporation, a subsidiary of Phillips 66 Company. Approximately 46M kg were produced in 1995 with a projected growth of 11% per year.[1]
PPS is marketed by different brand names and companies. Examples of these are: Ryton PPS by Chevron Phillips as cross-linked type of polymer; Fortron by Ticona, as a linear polymer.