PPS chemical resistance of

Transportation end uses are expected to become a significant outlet. Products under development include an engine valve cover, as are various housings such as those for od pumps, water pumps, starter motors, and certain transmission parts. These end uses employ PPS because it resists high temperatures and is also chemically resistant. Fuel system parts can employ the excellent chemical resistance of PPS, replacing nylon, if alcohol-based fuels are adopted to reduce emissions. 

The outstanding thermal stability and chemical resistance of PPS compounds have led to their use in applications ranging from food warmers to nuclear installations. Some of the harsh environments which these compounds are successfully withstanding are shown in the following applications ... 

Previous studies comparing PPS to other engineering thermoplastics established the relative short term (24-hour) chemical resistance of PPS moldings to a wide variety of chemical environments at 93°C. A portion of these results are given in Table... 

Table A.28 Chemical resistance of PPS [693], [1039], [1052] GF = Glass fibers, M = Mineral...

PPS finds uses in many heavy industrial applications, including some outside the arena of reinforced injection moulding compounds. The thermal stability and broad chemical resistance of PPS make it exceptionally well suited to service in very hostile ehemical environments. Besides moulded parts, PPS polymers find applications in fibre extmsion as well as in non-stick and chemical resistant coatings. 

The excellent corrosion resistance of PPS is also helpful for meeting the requirements of chemical sfabilify of fhe overall plates. In comparison wifh conventional graphite plates, the PPS-based plates have better mechanical properties and good corrosion resistance. 

The method of structural foam moulding permits the manufacture of foams with a compact skin and a cellular core. The properties of such mouldings depend, among other parameters, on the structure of the foam. This article reports on a study of the influence of density, specimen thickness, orientation and ambient temp, on mechanical properties and chemical resistance of injection monlded structural foams made from PP. Results are discussed with reference to relationships between structnre and properties. 5 refs. 

Damrongsakkul S, Sinweeruthai R, Higgins JS (2003) Processability and chemical resistance of the polymer blend of thermoplastic polyurethane and polydimethylsilox-ane. Macromolecular Symposia. 7th Eur Symp Polymer Blends, Lyon-Villeurbanne, 27-29 May 2002, pp 411-419... 

Automotive underhood environments are often antagonistic to plastics. Extreme temperatures coupled with exposure to oil, fuel, and coolants will permit only the most resistant of plastic compositions to be used. The heat and chemical resistance or PPS makes it a prime candidate for such cases. 

Coatings. The thermal and chemical resistance of polyphenylene sulfide nas led to a wide variety of applications as a coating material. Examples are cookware with heat-resistant, easy-release coatings containing PPS, valves and fittings coated with PPS for protection against corrosive chemicals, and electrical coils coated with PPS as a temperature-resistant insulation. 

LONG TERM CHEMICAL RESISTANCE OF 40% GLASS-FILLED PPS (Exposure Temperature, 93 0)... 

Polyfphenylene sulfide), sold by Phillips Chemical Company under the trade name Rylon, is a highly crystalline aromatic polymer (mp 285°C). It is obtained by the polycondensation of/7-dichlorobenzene and sodium sulfide. The symmetrical arrangement of -substituted benzene rings and sulfur atoms on the polymer backbone permits a high degree of crystallization. This, in addition to the extreme resistance of the benzene ring-sulfur bonds to thermal degradation, confers thermal stability, inherent nonflammability, and chemical resistance on PPS resin. 

The chemical resistance of carbon fiber reinforced PEEK and PPS composites have been determined [197]. 

DIN 8078 [467] Polypropylene (PP) pipes - PP-FI, PP-B, PP-R, PP-RCT - General quality requirements and testing Supplement chemical resistance of pipes and fittings... 

Besides water, the media flowing through PP pipe line systems include aqueous solutions, acids, bases, and solvents. Chemical resistance of polypropylene is influenced hy pigmenting, homogeneity, and structure of the crystalline phase. Figure 5.285 [831]. 

When the rubber is unvulcanised, the addition of rubber worsens the chemical resistance of the PP chemical resistance worsens as rubber content increases. RRPP mouldings have relatively poor resistance to petrol and other hydrocarbon solvents. The resistance of EP rubbers to aliphatic and aromatic solvents is poor also has poor resistance to animal and vegetable oils but good resistance to hydraulic fluids. 

Chemically Resistant Fibers. Fibers with exceUent chemical resistance to corrosive and/or chemical warfare agents or extreme pH conditions (eg, very acidic or very alkaline) were initially used for protective clothing. However, appHcations for filtration of gases and Hquids in numerous industrial faciHties are now the more important. For example, PPS is suitable for use in filter fabrics for coal-fired boilers because of its outstanding chemical and heat resistance to acidic flue gases and its exceUent durabUity under these end use conditions. Many high tenacity fibers are also chemically inert or relatively unaffected under a variety of conditions. Aramids, gel spun polyethylene, polypropylene, fluorocarbon, and carbon fibers meet these criteria and have been used or are being considered for appHcations where chemical resistance is important. 

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