PPS (Polyphenylene Sulfide)

Key properties of PPS

Polyphenylene sulphide is a semi crystalline, high temperature thermoplastic. Due to its chemical structure, PPS is a very resistant polymer with high mechanical strength and rigidity.

It is an ideal material of choice to produce complex parts with very tight tolerances. The polymer exhibits an excellent dimensional stability even when used under high temperature and high humidity conditions. In fact it shows a very low water absorption and low thermal dilatation.

It has excellent electrical insulation properties. Both the high-volume resistivity and insulation resistance are retained after exposure to high-humidity environments.

As we said, Polyphenylene Sulfide is a high-temperature specialty polymer. It can be resistant to 260°C for short time and used below 200°C for a long time. Most of the Polyphenylene Sulfide compounds pass UL94 V-0 standard without adding flame retardant.

This material has high strength, high rigidity and low degradation characteristics even in high temperature conditions. It also shows excellent fatigue endurance and creep resistance.

Polyphenylene Sulfide has good chemical resistance. If cured, it is unaffected by alcohols, ketones, chlorinated aliphatic compounds, esters, liquid ammonia etc. however, it tends to be affected by dilute HCl and nitric acids as well as conc. sulphuric acid. It is insensitive to moisture and has good weatherability.

Polyphenylene Sulfide has however, a lower elongation to break, a higher cost and is rather brittle.

PPS main additives

Polyphenylene sulphide is largely available in different grades and usually developed for injection moulding. Semi-finished products, such as rods and plates, are available too with different kind of additives, to improve the main characteristics. We can actually supply:

• Filled 40% glass fibres: because of the high level of glass fibre reinforcement, PPS GF40 demonstrates excellent rigidity and very high strength at high temperatures compared to unmodified PPS. High thermal stability, high dimensional stability, very good chemical resistance, good electrical and thermal insulation and good resistance to sterilization rounds out the property profile of this modified PPS. These material properties make glass filled PPS suitable for use in parts that are exposed to high static loads over long periods in high temperature conditions. However, the inherant chemical structure along with the addition of glass fibres tends to create toughness issues with this material. As glass fibres tend in some cases to have a marked abrasive effect on mating surfaces, this PPS composite may be less suitable for sliding applications. Material is usually available in black colour;
• Bearing grade: carbon fibres, PTFE and graphite. Through PPS SL, we can offer a filled Polyphenylene Sulfide, which is a specially modified for use in sliding applications. The material contains 10% each of PTFE, graphite and carbon fibres which are added to the PPS to facilitate bearing and wear applications. The additives of the PPS compound result in an optimum coefficient of friction value, that makes the material ideally suited to dry running conditions. So PPS SL is a bearing grade PPS that is suitable for high load applications, under high temperatures, and the effects of chemicals and steam. The PPS compound perfectly combines good mechanical properties with excellent thermal and chemical resistance properties.
• Filled glass fibre and solid lubricant. PPS GF SL (colour: deep blue) demonstrates an excellent combination of properties including wear resistance, load-bearing capabilities and dimensional stability when exposed to chemicals and high temperature environments.

Thanks to the uniformly dispersed internal lubricant, PPS GF SL exhibits an excellent wear resistance and a low coefficient of friction. It overcomes the disadvantages of virgin PPS caused by a high coefficient of friction and of a glass fiber reinforced Polyphenylene Sulfide which causes premature wear of the counterface in moving-part applications.

Miscellaneous information

Polyphenylene Sulfide is largely used in medical equipment and fluid controls. In some case and by certain producers it can certified NSF and KTW for potable water. Moreover, it can be certified according FDA.

Most famous brand names

Polyphenylene sulphide is usually available, upon request, in semi-finished products, such as rods and plates. Most famous trade name are:

• Tecatron®
• Sustatron®
• Techtron®

PPS in few words.

Special properties:

• Good heat deflection temperature;
• Resistance against high energy radiation;
• Good chemical resistance;
• High strength;
• High stiffness;
• High dimensional stability;
• High creep resistance.

Used in:

• Aircraft and aerospace technology;
• Electronics;
• Mechanical engineering;
• Oil and gas industry;
• Chemical technology.

Applications:

• Insulators;
• Bushings;
• Pump components;
• Chemical components;
• Electronical components.