Development status and progress of special enginee

This paper briefly describes the development status and progress of special engineering plastics

special engineering plastics usually refer to some plastic materials with superior and unique properties compared with general engineering plastics, which have not been mass produced yet, relatively narrow uses, and plastic long-term use temperatures above 200 ℃, such as polyimide (PI), polysulfone (PSF), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), liquid crystal polymer (LCP) and polyether sulfone (PES). The main markets of these materials are electronics, electrical appliances, automotive industry, military products and compressor parts

1 polyimide

polyimide (PI) has a very stable aromatic heterocyclic structure, which makes it show excellent resistance to temperature and low temperature compared with other polymer materials. PI synthesized from biphenyldianhydride and p-phenylenediamine has a thermal decomposition temperature of 600 ℃, and can be used for a long time below 333 ℃, but it will not embrittle at - 269 ℃. PI has high mechanical strength. The tensile strength of homobenzene type PI film can reach 170Mpa, and that of biphenyl type can reach 400MPa, and the change is small with the increase of temperature; Good radiation resistance; Excellent dielectric properties; Stable chemical properties, very stable to acids and bases; In addition, PI has strong creep resistance and excellent friction performance

in 2003, the global consumption of PI was about 3.15 million tons, with more than 50 major manufacturers. At present, the consumption of the United States, Western Europe and Japan has exceeded 20000 t/a, including 1.13 million t/a in the United States. It is expected that the consumption of the United States, Western Europe and Japan will reach 2.17 million T/A in 2004. There are 14 factories in the United States, 11 factories in Western Europe and 13 factories in Japan that produce PI. In addition, Russia, China, India, South Korea, Malaysia and Taiwan Province of China all produce and consume PI in small quantities. Polyetherimide (ulterm) accounts for about 70% of the PI demand in the United States. Due to its good performance and processing characteristics, it tends to compete with polyethersulfone, polyphenylene sulfide and other aromatic pi. It is expected that the global demand for PI will increase at an average annual rate of about 10% in the next few years

China has almost started the research and development of PI at the same time as the world, and has developed several major varieties of PI, such as benzene type, partial anhydride type, biphenyl dianhydride type, bisphenol A dianhydride type, monoether dianhydride type, ketone dianhydride type, etc., which have been preliminarily applied. At present, there are nearly 20 manufacturers, and the production capacity has exceeded 800t/a. In 2002, the PI film market became stronger, and the production capacity has reached 750t/A. in 2003, six manufacturers increased the capacity by 400t/a, and the number of manufacturers expanded to 26. Four manufacturers have exported films. With the export of copper foil, the national export volume is nearly 70t/a. At present, the main manufacturers include Shanghai synthetic resin Research Institute, Changshu Aerospace insulation material factory, Baoying Yabao insulation material factory, Northwest Chemical Industry Research Institute, Sichuan University Experimental Factory, etc

the domestic output in 2003 was about 400t. China has also developed rapidly in PI molding materials in recent years. Shanghai synthetic resin research institute has developed a variety of products, Northwest Research Institute of chemical industry produces bismaleimide, and Jilin Changchun Yinghua Institute and Jilin high tech company produce biphenyl PI molding materials. Compared with foreign products, many PI varieties in China have competitive advantages in price, so China's electrical insulation film market is basically occupied by domestic products, and China has begun to export products to foreign countries, such as Northwest Research Institute of chemical industry exporting 30t bismaleimide to Europe every year, and Shanghai synthetic resin research institute also exporting a small amount of products every year. At present, thermoplastic Pi is mainly used in automobile engine parts, oil pump and air pump covers, high-temperature socket connectors for electronic/electrical instruments, printed circuit boards and computer hard disks, integrated circuit chip carriers, aircraft internal cargo systems, etc

a thermoplastic PI developed by Nanjing University of technology and funded by Changzhou Guangcheng New Plastic Co., Ltd. has been successfully developed. The thermoplastic PI overcomes the defects that most PI are insoluble and difficult to process, shows good hot processing characteristics, and can be molded by hot molding, extrusion and injection; It can be compounded with carbon fiber, glass fiber, polytetrafluoroethylene, graphite, etc. to further improve the tensile, self-lubricating and wear-resistant properties of the material. It is an ideal material that can replace metal, ceramic thermosetting resin and low-temperature thermoplastic under specific conditions. At present, the technology has been industrialized and has formed a capacity of 200t/a

PI in China has developed rapidly with the development of national defense industry, and its research and application in some fields have reached the world level. The gap with foreign advanced countries is mainly reflected in the small scale (at present, the largest production unit in China is 100t/a, while the developed countries are basically 1000 t); Unstable product quality; There are few varieties. At present, the main products are polyisophthalide films, and the application fields are mainly films and molding materials. There are many kinds of foreign products, such as film, molded parts, coatings, adhesives, enamel, foam and fibers. While developing the existing varieties, China should vigorously develop major resin varieties with large consumption, such as polyetherimide, polybiphenyltetraformimide, thermoplastic PI and POLYBISMALEIMIDE

2 polysulfone

polysulfone (PSF) resin is a thermoplastic engineering plastic prepared by polycondensation with bisphenol A and 4,4 '2 dichlorodiphenylsulfone as raw materials. Polysulfone material has good rigidity and toughness, and can be used for a long time in the temperature range of - 100 ℃ ~ 150 ℃. It has excellent creep resistance, can resist the corrosion of inorganic acid, alkali and salt solutions, can resist ionic radiation, is non-toxic, has good insulation and self extinguishing, and is easy to form and process

the world's major PSF production enterprises include BP, BASF, ICI and the Russian SHEVCHENK plant. The total production capacity of global PSF is about 3.15 million t/a, and the total consumption is 30000 T/A. It is estimated that by 2005, the global consumption of PSF resin will reach more than 40000 tons. At present, the main consumer markets of PSF products in the world are concentrated in the United States, Japan and Western Europe. In terms of use, the consumption in aerospace and automotive fields accounts for 32%, electronics and appliances 36%, precision machinery 10%, food industry 8%, industrial equipment 8%, medical devices 4%, and others 2%

in the development of PSF modified materials, in addition to glass fiber reinforced high-rigid PSF composites, many high-performance PSF alloys have been developed, such as polysulfone/polyamide, Polysulfone/rubber, polyethersulfone/Polyphenylene Sulfide and polyethersulfone/polycarbonate. Sumitomo chemical company of Japan added polytetrafluoroethylene and hydroxybenzoate to polyether sulfone, which can greatly improve the elastic modulus and wear resistance of the material. The Polysulfone/polyether ketone block copolymer developed by BASF has good chemical corrosion resistance and high temperature resistance. Add 0. 5% to PSF products 5% brominated polyphenylene oxide can obtain transparent flame retardant products with flame retardant grade of V - 0. The Polysulfone/polyethersulfone (ultrason s and ultrason E) products of BASF company have good dimensional stability, water and oil resistance at high temperature. They can work continuously at 190 ℃ and the short-term temperature resistance can be as high as 390 ℃. Recently, the company has expanded the production capacity of this product from 3000t/a to 5000t/a. BASF of Germany has launched a new polyether sulfone ul2t rason brand with special formula, which is used for the production of food utensils that can withstand the high temperature of microwave heating and boiling. Due to the adoption of a new anti ultraviolet (UV) stabilizer, this product improves the transparency of PES brand. This UV stabilizer can ensure that the material will not change color and resist heat and aging for 30 years. The use temperature range is - 14 ℃ ~ 220 ℃. The prepared plate can be taken out of the refrigerator and directly put into the microwave oven

the current production capacity of PSF resin in China is 1500t/a, and the output is maintained at about 1000t/a. There are few brands of PSF resin in China, which is mainly used in medical devices, food processing machinery, electronic instruments, textiles and other industries. Compared with foreign countries, the production process, including monomer synthesis, polymerization, post-treatment and recycling, needs to be further improved and improved, and its application in the automotive industry, aerospace and other fields also needs to be further promoted

3 polyphenylene sulfide

polyphenylene sulfide (PPS) has excellent heat resistance, flame retardancy, insulation, high strength and hardness, excellent mechanical properties, and good dimensional stability of products. It can be processed by a variety of processing and forming methods and can be precision formed. Because PPS has good compatibility with inorganic fillers, reinforcing fibers and other polymer materials, it can be made into different reinforced filling varieties and polymer alloys, which are widely used

311 world production capacity and demand

foreign PPS production capacity is 60000 t/a, and the output is about 40000 t/A. the output and demand are basically balanced, but the demand is increasing at an annual rate of 20% ～ 30%. For the production of this instrument in the United States, it is recommended to use PPS resin at an ambient temperature below 25 ℃, which is 1.16 million t/a, accounting for about 40% of the world's total output, and the annual consumption is about 1.14 million T, accounting for 38% of the world's total consumption. Japan produces about 1.18 million t/a of PPS, accounting for 45% of the world's total output, and its annual consumption is about 1.12 million T, accounting for 30% of the world's total consumption. It is estimated that the total consumption of PPS in the world will reach about 70000 tons in 2005

the world's PPS manufacturers mainly include Phillips of the United States, the oil company with a global EPS output of 6million tons per year (with a capacity of 9800t/a), Fort Ron of the United States (with a capacity of 5500t/a), Bayer of Germany (with a dust cover when producing unsuitable instruments, with a dust invasion energy of 5000t/a), Toray 2 Phillips of Japan (with a capacity of 8500t/a), Wuyu chemical industry company of Japan (with a capacity of 8000t/a) Japan's Tojo 2 Baoshi Valley company (with a capacity of 5000t/a), Japan's greater Japan ink chemical company (with a capacity of 3000t/a) and Japan's dongran Petrochemical Company (with a capacity of 7200t/a), etc. Toray industries' PPS capacity in Ehime, Japan, reached 600t/a in 2004

Fort Ron (a joint venture between Ticona and Wuyu chemical company) will build new PPS units in the United States or Europe within five years. At the same time, the PPS capability in Wilmington will be divided into two stages (200