Poly(p-phenylene sulfide)
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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]
Chevron Phillips manufactures the most common form in industry under the brand name Ryton.
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[edit] Fiber characteristics
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.
[edit] Production
The Federal Trade Commission definition for sulfar 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 sulfide with p-dichlorobenzene:
- ClC6H4Cl + Na2S → 1/n [C6H4S]n + 2 NaCl
The process for commercially producing PPS (Ryton) was developed by Dr. H. Wayne Hill Jr. and Mr. James T. Edmonds at Phillips Petroleum Company.[2] N-methylpyrrolidone is used as the reaction solvent since it is stable at the high temperatures requires 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 both staple and filament fibers.
The first U.S. Commercial Sulfar Fiber was produced in 1983 by Phillips Fibers Corporation, a subsidiary of Phillips 66 Company.[citation needed] 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: Fortron by Ticona, as a linear polymer, Ryton PPS by Chevron Phillips, as cross-linked type of polymer, and Sulfar.
[edit] References
- ^ a b David Parker, Jan Bussink, Hendrik T. van de Grampel, Gary W. Wheatley, Ernst-Ulrich Dorf, Edgar Ostlinning, Klaus Reinking, "Polymers, High-Temperature" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH: Weinheim. DOI: 10.1002/14356007.a21_449
- ^ H Wayne Hill Jr., James T. Edmonds, to the Phillips Petroleum Company Research Center (Bartlesville, Oklahoma, US). Patent 3,354,129, 1963. issued November 21, 1967
