A brief introduction to.PVC:
PVC, referred to as PVC, for thermoplastic resin. And steel, timber, cement, and says the four basic building materials, and PP polypropylene (polypropylene), PE (polythylene or wrist polyethylene), ABS (acrylonitrile butadiene styrene acrylonitrile - butadiene - styrene (plastic), polystyrene polystyrene (PS) and said the top five general-purpose resin, is the largest chlor alkali industrial organic chlorine consuming products.
1 basic physical and chemical properties of polyvinyl chloride
Polyvinyl chloride (chloride polyvinyl), referred to as PVC, for thermoplastic resin. With steel, timber, cement, and says the four basic building materials, and PP, PE, ABS, PS and said the top five general-purpose resin, is the largest chlor alkali industrial organic chlorine consuming products. PVC has stable physical and chemical properties, insoluble in water, alcohol, gasoline, gas and water leakage of low; at room temperature below the nitric acid resistant to any concentration of hydrochloric acid, less than 90% sulfuric acid, 50 - 60% and 20% caustic soda solution, with certain chemical corrosion resistance; salt fairly stable, but can be dissolved in organic solvent ether, ketone, chlorinated aliphatic hydrocarbons and aromatic hydrocarbons. In addition, the optical and thermal stability of PVC was worse than that of 100 or more hours of exposure to the sun, and it could be decomposed to produce hydrogen chloride, and the mechanical properties decreased rapidly. So the stability of the heat and light in the practical application must be added.
2 PVC can be divided into soft PVC and hard PVC. Hard PVC which accounts for about 2/3 of the market, soft PVC accounted for 1/3. Soft PVC is generally used in the floor, ceiling and the surface of the leather, but due to soft PVC contains a soft agent (which is the difference between the soft PVC and hard PVC), easy to become brittle, not easy to save, so its use is limited to the scope of. Hard PVC does not contain soft agent, so it is flexible, easy to shape, not easy to brittle, non-toxic, no pollution, save time, so it has great development and application value. Below are referred to as PVC. Soft PVC is used to make a vacuum blister film, for all kinds of surface packaging, so it is also known as the decorative film, adhesive film, used in building materials, packaging, medicine and many other industries. Which building materials industry accounted for the largest proportion, 60%, followed by the packaging industry, there are several other small range of applications.
Two.PU discovery and use
In 1849, German chemist Woertz (Wurze) was synthesized by the reaction of alkyl sulfate and potassium sulfate by the synthesis of alkyl isocyanate. Hoffman (A.W.Hoffmann) was successfully synthesized in 1850. Later Hentschel (Hentschel), et al. In 1884, the synthesis of isocyanate.
At that time, the isocyanate was not found to have any use value, and it was not used in polymer chemistry. Until the German chemist Bayer (Bayer) and when lab colleagues were repeated studies, can discover the synthesis of polyurethane and polyurea compound isocyanate, but is practical is still little. In 1933, Carlo Seth (W.H.Carothers), the United States of America invented the "nylon" to stimulate the german. Germany wanted to invent a product that was able to compete with it soon. This has also accelerated the then Bayer polyurethane research and development work, they found that chain of polyurethane with thermal plasticity, spinnability and can be made of plastic and fiber. At that time, the commodity name was U Perlon and U Igamid. With the continuous improvement of the PU material process, the material is more environmentally friendly and more durable. PU materials in the wire and cable, leather, aerospace products, automotive products, building materials products widely used.
Three. Classification: brass, copper bronze, copper, copper nickel alloy.
High price of copper. Copper is copper, also known as copper, with good electrical conductivity and thermal conductivity, plasticity excellent, easy to hot and cold pressure processing and used extensively in for good conductive wires, cables, brush, electric spark special electric corrosion of copper and other manufacturing products. Red copper. Sulphide or oxide copper ore to copper smelting, casting and making money available to objects. Ming song Yingxing's "Heavenly Creations": "where the copper and copper for the world, coming out and released, only the red copper. In calamine or Japanese lead and changing color to brass; to arsenic and other medicine refining copper nickel alloy; alum, nitrate and other drug smelting bronze; wide tin and copper ring; Japanese lead and write [purge] cast copper. At the beginning of a matter of copper." Guo Moruo's Chinese history compiled the first chapter 3 Section 2: "they smelt the copper component very pure, in addition to trace (0.1 - 0.2%) impurities natural, no artificial addition of tin or lead to alloy. Although the hardness of copper is poor, but can be made directly through the beat of tools and accessories." Copper is copper. Because of its color is purple red and named. See various properties of copper. Copper was purple by name. It doesn't have to be a pure copper, sometimes also added a small amount of deoxidizing elements or other elements, to improve the quality and performance and also was included into the copper alloy. China's copper processing material according to the composition can be divided into ordinary copper (T1, T2, T3, T4), oxygen free copper (TU1, TU2 and high purity, vacuum oxygen free copper), deoxidized copper (TUP, TUMn), adding small amount of alloy elements of special copper (arsenic copper and tellurium copper, silver, copper). Copper electrical conductivity and thermal conductivity after silver, widely used in the production of conductive, heat transfer equipment. Copper in the atmosphere, seawater and some non oxidative acid (hydrochloric acid, sulfuric acid, alkali, salt solution and various organic acids (acetic acid, citric acid), good corrosion resistance for the chemical industry. In addition, copper has good weldability, can be cold, thermoplastic processing into various semi-finished products and finished products. In twentieth Century 70, copper output more than other types of copper.
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