Chemical materials

2017-08-07 12:35:22 阅读 3

Overview


The above-mentioned industrial and agricultural production and living improvement, are inseparable from the material. According to statistics, by 1984, the world has about 9 million chemical substances, of which about 43 for the material. Although the number of materials, if classified by chemical composition, can be summarized as metal materials, inorganic non-metallic materials and polymer materials three categories. There is also a composite material listed as the fourth category, or as it is derived from the three categories of a new class of materials. In general, in addition to metal is the production of metallurgical products, the rest are chemical production materials.


Nonmetal


Inorganic nonmetallic materials


Divided into two types of traditional materials and new materials. The former is mainly silicate material; the latter composition of diverse, rapid development.


Silicate materials refer to glass, ceramics, cement and enamels. They are based on silicate-containing ore as raw materials for production, widely used as building materials, can also be used as daily necessities and arts and crafts products. Glass and ceramics, although brittle and brittle is its main shortcomings; but because of easy access to raw materials, the production process is simple, the product of good chemical stability, but also has high hardness, heat and corrosion resistance, etc., use a very wide range, Big, and still in constant development.


New inorganic nonmetallic materials


Mainly special ceramics. With the industrial and agricultural, military industry and the development of science and technology, new structural ceramics has come out. They are composed of different oxides, silicides, carbides, nitrides, fluorides, borides and other components. Mainly including high temperature materials, electrical insulation materials, ferroelectric materials, piezoelectric materials, semiconductor ceramic materials, the use of special, little output, but the value is high. The 21st century has developed a ceramic engine for the car, can improve the gas temperature to 1400 ℃ above, to improve efficiency, energy conservation is of great significance. The material of the manufacturing process is characterized by: the purity of raw materials demanding, composition, microstructure and product surface and interface must be strictly controlled, the shape is also meticulous and complex, requiring precision machining. Such new materials are based on high-level science and technology on the basis of success.


Polymer material


Mainly include plastic, chemical fiber and rubber three categories. Among them, many varieties of synthetic materials, they are produced by the petrochemical monomer, through the polymerization reaction made. Some with natural materials can not reach the special performance, widely used in industrial and agricultural production and daily life, so the development of fast. 30 years of world production of polymer materials has not yet exceeded 100kt, to the 80's has reached about 80Mt, plastic accounted for 3/4. As the plastic than the metal light, so by volume, its output has long been beyond the metal material.


The base material of the polymeric material is synthetic resin. The plastic system is light (usually only 1/9 of steel), corrosion resistance, heat resistance, electrical insulation is good, easy processing and forming, in recent decades a large number of metal, glass, paper, wood and so on. Plastic film is mainly used as a packaging material, in agriculture, is also widely used. Plastic pipe used as a large number of oil, water pipes. Car shells and parts are also made of plastic. Floors and doors and windows made of polyvinyl chloride are five times more resistant to abrasion than wood. Plexiglass density is half of ordinary glass, and the impact strength of up to 17 times, can be used as the windshield of the aircraft. Plastic is also used in a wide range of electronics and electrical industries, making wires, cables, switches and instrumentation housings. Plastic products can be said to have been deep into people's production and life in every corner. There are some synthetic resin with a special function, known as functional polymer materials, such as conductive materials, semiconductor materials, photosensitive resin, light guide materials and superconducting materials, causing great interest.


Chemical Fiber


Including man-made fiber-borne fiber as raw materials produced by chemical processing, in the 20 ~ 30 years has been popular, but its production by natural fiber sources. Synthetic fiber products are in the mid-40s, the source of raw materials for the rich petrochemical products. There are many varieties of chemical fiber, there are filaments, short wire, bristles, stretch yarn and a variety of special-shaped silk. They can be pure spinning, blending, and thus a wide variety of fabrics, and high production efficiency, not subject to natural conditions, effectively solve the contradiction with the grain and cotton. Production of tons of chemical fiber, can be equivalent to 30 million mu (1 acres = 666.6m2) cotton production of cotton a year; or cut by 250 million sheep a year of wool. By the 1980s, two thirds of the world's textiles were made of chemical fibers. Some of the polymer made of hollow fiber used as a separation membrane, in desalination, gas separation, preparation of ultra-pure substances and biotechnology, etc., is of great significance.


rubber


Is a strategic material. Natural rubber only grows in tropical and subtropical regions, non-rubber countries to consider the wartime will be blocked, are attached to the petrochemical industry based on the synthetic rubber industry. Synthetic rubber varieties, and some varieties than natural rubber has a better heat, cold, oil and other properties. The maximum consumption of rubber is to do tires, in addition to the production of hose, tape, rubber shoes, mold silicone rubber, and latex products. Rubber is a variety of equipment indispensable sealing material. Since the 1970s, natural rubber production is basically stable in the 3 ~ 3.5Mt, and synthetic rubber production in the 1970s has reached 6Mt, 80 years to 8Mt, and there is still continued trend.


Composites


Is a new type of structural materials. It is characterized by volume specific strength, volume specific stiffness and corrosion resistance are more than metal materials. It consists of synthetic resin, metal or ceramic and other inorganic materials such as inorganic or organic synthetic fiber reinforced material composed of complex material. Substrates and reinforcements are available in a variety of ways, so that they can be selectively blended to produce a variety of composite properties that meet the requirements, giving chemical materials a broader prospect.


分享到: