Poly(p-phenylene sulfide)
- Poly (thio -p- phenylene)
- PPS
Thermoplastic
Fixed
Unreinforced 1.35 g/cm3
About 285 ° C
90 ° C
4000 MPa
0.05 %
Very good chemical resistance to various fuels, oils, ethanol, Freon, xylene
0.5 10-4 K-1
Polyphenylene sulfide ( PPS abbreviations, and poly (thio -p- phenylene) called ) is a high temperature resistant thermoplastic with the general formula ( SC6H4 ) n Technically, it is generally prepared by polycondensation of 1,4- dichlorobenzene with sodium sulfide in an aprotic solvents such as N-methylpyrrolidone.
History
In 1888 discovered Charles Friedel and James Mason Crafts PPS, which was a very early time point for a polymer. End of 1940, attempts have been made on a large scale to produce the material, but only in 1967 was developed by Edmonds and Hill of Phillips Petroleum Company, a method to synthesize PPS of 1,4- dichlorobenzene and sodium sulfide. This development marks the actual commercialization of PPS. 1973 was taken by Chevron Phillips in Texas the first commercial plant in operation. Since then, the name Ryton for moldable PPS.
After 1984, the basic patents had expired, new plants were built by competitors worldwide. These were then also able not only to produce cross-linked material, as it was known in the market so far, but also the first products with a linear chain structure came on the market.
Properties
PPS is a semi-crystalline high performance plastic. By combining aromatic monomer units via sulfur atoms are produced particularly resistant polymers with good mechanical properties are retained even at temperatures well above 200 ° C, so that a continuous use, depending on the load up to 240 ° C is possible. Short term also loads at temperatures be withstood up to 270 ° C. Outstanding addition, the chemical resistance of the PPS to almost all solvents, many acids and alkalis as well as due to atmospheric oxygen even at high temperatures.
PPS has not only a low water absorption, also has a good dimensional stability and inherent flame resistance. It has excellent electrical properties (insulator ) is, for most liquids and gases highly impervious ( impermeable ), even at higher temperatures has only a low creep and is due to its good flowability for long, narrow moldings and complex tool geometries.
There are basically two different types of PPS: linear and cross-linked. While the crosslinked PPS, the branched polymer chains are reversibly connected to each other via physical cross-linking points, the chains of slightly branched linear PPS store in highly ordered superstructures. This morphological structure is reflected mainly in the mechanical properties. So has linear PPS especially higher toughness and elongation at break as a networked.
The thermoplastic, which is typically an electrical insulator can be converted into an organic semiconductor by doping.
Use
Polyphenylene find particularly used for mechanical, electrical, thermal and chemical heavy-duty molded parts in the electronics and automotive sectors.
Linear PPS can be formed by a wide range of processing techniques ( blow molding, extrusion, injection molding ) into components, about 80%, but generated in the injection molding. In contrast, there are at cross-linked PPS property changes that lead to restrictions in processability. It is mostly only injection molded and only very limited extrudable.
For 2007, with a global consumption of 50,000 t and expected an increase in demand.
Trade names
- Tedur ® ( linear PPS ) by Albis Plastic
- DIC.PPS of DIC Corporation
- Fortron ® from Ticona, linear material
- Petcoal ® by Toso
- Ryton ® by Chevron Phillips, which is positioned mainly as a cross-linked material on the market
- Torelina ™ Toray
Standardize
- ISO / DIS 28078-1 Draft, 2008-2002 - Plastics - polyphenylene sulfide ( PPS ) molding and extrusion materials - Part 1: Designation system and basis for specifications
- ISO / DIS 28078-2 Draft, 2008-2002 - Plastics - polyphenylene sulfide ( PPS ) molding and extrusion materials - Part 2: Preparation of test specimens and determination of properties