PPS Development Is Promising

By Zhang Qisheng, Tianjin Petrochemical Co., Ltd.

Major producers of polyphenylene sulfide (PPS) in China include Sichuan Deyang Science & Technology Co., Ltd., Tianjin Institute of Synthetic Materials Industry, Sichuan Changshou Chemical General Plant, Guangzhou Research & Design Institute of Chemical Industry, Guangzhou Chemical Reagent Factory, Sichuan Special Engineering Plastics Plant and Beijing Research Institute of Chemical Industry.
Sichuan Huatuo Science & Technology Co., Ltd. has constructed a 1 420 t/a unit for PPS linear resin with high molecular weight. It was the first pressurized-process PPS unit in China with capacity exceeding 1 000 t/a. Various technical indexes of the product reach international levels.
Sichuan Deyang Science & Technology Co., Ltd. has constantly expanded its PPS production scale in recent years. Two new 6 000 t/a units are already complete, and a 22 000 t/a unit is now under construction.
PPS imported by China today comes mainly from Kureha Chemical Industry Co., Ltd. of Japan and Phillips Petroleum Company of the United States. Major consumers of the imports are Chinese-foreign joint ventures.
Around 50% of PPS in China is used to produce injection-molded products such as electronic/electric parts, automotive components, petrochemical high-grade anticorrosive materials, medical equipment components and mechanical sealing parts; 35% is used to produce fibers (such as industrial filtration materials), carbon fiber and aromatic composites; 10% is used to produce coatings for corrosion prevention of oil transmission pipelines; 5% of PPS is used to produce films for computer insulation and long-distance transmission of high-voltage power.
PPS is a new material with firm development support from the state, extremely bright application prospects and huge development potential in many sectors.
In the environmental protection sector, PPS can be used in filtration fabrics in making high-temperature flue bag de-dusting equipment for industrial coal-fired boilers. As requirements on coal-fired boiler flue emission are getting more stringent in China, the bag de-dusting technology has gained extensive application and will be disseminated nationwide on a large scale.
As the automotive sector pursues light weight and low cost, components made of PPS, with good mechanical properties, high dimensional precision, high-temperature resistance and corrosion resistance, are more and more numerous, and the application potential is huge. In foreign countries, the automotive sector consumes over 30% of all PPS, whereas the proportion is less than 10% in China. Some Chinese automotive component enterprises are making trial use of domestic PPS in manufacturing components. The consumption of such components has doubled and redoubled in recent years, opening PPS marketing opportunities in the automotive sector.
In the textile sector, PPS fiber can be used in making high-performance industrial filtration cloth for processing hot corrosive reagents. PPS mono-filament or multi-filament fabrics can also be used as de-fogging materials. Moreover, PPS fiber can also be used in drying canvas, sewing thread, protective cloth, heat-resistant clothing materials, electric-insulating materials, electrolytic diaphragms, brake friction linings and radiation-resistant spaceflight cloth.
The electronics/electric sector was first to use PPS and is now the biggest consumer of PPS. PPS is often used to make components for precision gauges and instruments. PPS is also used in making electronic cladding materials and mechanical sealing materials with excellent properties. In the manufacture of unique semiconductors PPS replaces epoxy resin as cladding material or is used to make special paper. For household electric appliances, PPS film is the best insulating material, having reached F grade. With today’s increasing precision of manufacturing various electronics, gauges and instruments, applications of PPS in this sector will become more and more extensive, and the market potential is huge.
In the national defense sector, PPS also has extremely extensive applications in ships, aviation, spaceflight and military equipment. In addition to the manufacture of conventional weapons, PPS is used to produce vertical tail wings of fighters, combustion chambers of missiles and connectors for airplanes and spacecraft, especially in the manufacture of the main components for stealth fighters and bombers, and nuclear radiation resistant components for nuclear submarines. PPS can also be used to make rifles, helmets, military tents, containers, astronaut utensils and anti-corrosion and anti-abrasion components for warships and submarines.
In the chemical sector, PPS injection-molded products are extremely suitable for use as liners of chemical equipment. They can be used to make dilute sulfuric acid hydrolysis tanks, exhaust valves and discharge valves with high-temperature resistance and corrosion resistance, as well as mechanical parts such as pump shells, rotors, windmills, blades and filters. PPS can be blended and modified with various resins such as PBT, PTFE, PES, PC, PEK-C, PPSK, PPE and PE. Applications of PPS in the chemical sector are therefore expanding.
In the construction sector, PPS reinforced by glass fiber or carbon fiber has excellent mechanical strength and flame-retarding behavior. It can be used where antistatic material or material with high-frequency ray resistance is required. Boards made of such materials can be used in floors, walls and equipment materials in nuclear installations, high-frequency environments, IT rooms and high-power transmission/receiving stations. PPS can also be used to make construction materials with various unique applications. Moreover, PPS’s low relative molecular mass allows it to be used to produce special coatings.
PPS output in China still falls far short of domestic market demand. With the greater attention paid by the state to environmental protection, corrosion prevention and national defense, the PPS market in China will rapidly develop further by leaps and bounds.