Polyphenylene Sulfide (PPS)
Main Properties of PPS
◆ [Excellent Heat Resistance] Its melting point exceeds 280℃, heat distortion temperature exceeds 260℃, and long-term service temperature ranges from 220 to 240℃. It degrades in air at 700℃ and retains 40% of its weight in inert gas at 1000℃. Both short-term heat resistance and long-term thermal stability in continuous use surpass all currently available engineering plastics. Specially modified varieties can achieve a heat distortion temperature of over 350℃.
◆ [Self-Extinguishing] Polyphenylene sulfide has a flame retardancy rating of UL94-0, with an oxygen index (LOI) > 57%. The chemical structure of polyphenylene sulfide gives it excellent flame resistance without the need for added flame retardants.
◆ [Good Mechanical Properties] It has very high rigidity, a high surface hardness (Rockwell hardness > 100HR), tensile strength > 170MPa, flexural strength > 220MPa, notched impact strength > 16MPa, and a flexural modulus > 3.5×10^4, along with excellent creep resistance and fatigue resistance.
◆ [Excellent Chemical Resistance] Currently, no solvents have been found that can dissolve polyphenylene sulfide below 200℃, and it exhibits strong resistance to inorganic acids, bases, and salts.
◆ [Good Dimensional Stability] It has a very low molding shrinkage rate of less than 0.0025%, moisture absorption of less than 0.05%, and a small linear thermal expansion coefficient. It maintains good dimensional stability even under high temperature and high humidity conditions, making it widely applicable in machinery, chemical industry, instrumentation, aerospace, and maritime fields.
◆ [Excellent Electrical Properties] Polyphenylene sulfide retains excellent electrical properties under high temperature, high humidity, and high frequency conditions, with a volume resistivity of 1×10^16Ω.cm, surface resistivity of 1×10^15Ω, and electrical strength > 18KV/mm.
◆ [Radiation Resistance] It has a radiation resistance of Gy1×10^8, making it an unparalleled new material compared to other engineering plastics, and an ideal material for electronic, electrical, mechanical, instrumentation, aerospace, and military applications, particularly for radiation-resistant needs.
◆ [Good Processing Characteristics] PPS resin has a low melt viscosity, good flowability, and easily wets and contacts with fiberglass. Therefore, fillers are easy to use, and the fiberglass or inorganic filler reinforced injection-grade pellets made from it exhibit extremely high resistance to stretching, impact, bending, and ductility. It can be uniformly molded above its melting point.
◆ [Good Adhesion to Metals and Non-Metals] PPS exhibits very high bonding strength to materials such as glass, aluminum, titanium, and stainless steel, achieving a bonding level of 1. Its bonding performance with glass is particularly good, making it suitable for lining chemical equipment.
Main Applications of PPS
Electronics and Electrical: Packaging of microelectronic components, connectors, terminal blocks, sockets, coil frames, trimmer capacitors, fuse bases.
Mechanical Instruments: Pump housings, impellers, bushings, gears, pulleys, universal joints, sealing gaskets, flanges, counters, level gauges, flowmeter components.
Automotive: Temperature sensors, evaporators, purge pumps, seat bases, water tank chambers.
Home Appliances: Electric fans, microwave oven brackets, dryers, coffee pots, rice cookers, hot air tools, curling irons, air conditioning compressors.
Military: Manufacturing fighter jets, vertical tails, combustion chambers, connectors for aerospace and aviation, coil frames, dashboard components, especially key components for stealth fighters and bombers. Parts for nuclear submarines resistant to nuclear radiation, supports, helmets, military tents, utensils, astronaut supplies, corrosion and wear-resistant components for warships and submarines, new armored vehicles under development in the United States (currently in production) and plastic tanks developed in the UK (in experimental phase), etc.
Fibers and Films: Blending PPS fibers with other synthetic fibers can produce high-performance industrial filter fabrics and radiation-resistant aerospace fabrics. PPS films are excellent F-class insulation materials, suitable for making capacitors, impedance electronic components, flat coil frames, wire coatings, covers, evaporator diaphragms, heat-sensitive printing materials, flexible disks, and photoconductive films for electronic photography.
