Polypropylene is a polymer formed by addition polymerization of propylene. It is white waxy material with transparent and light appearance. The chemical formula is (C3H6) n, the density is 0.89 ～ 0.91g/cm3, it is flammable, the melting point is 189 ℃, it is softened at about 155 ℃, and the use temperature range is – 30 ～ 140 ℃. It can resist the corrosion of acid, alkali, salt solution and various organic solvents below 80 ℃, and can be decomposed under high temperature and oxidation. Polypropylene is widely used in the production of clothing, blankets and other fiber products, medical devices, automobiles, bicycles, parts, transmission pipelines, chemical containers, etc., as well as food and drug packaging.
Characteristic
Polypropylene, abbreviated as PP, is a colorless, odorless, non-toxic, translucent solid substance. Polypropylene is a kind of thermoplastic synthetic resin with excellent performance, which is a colorless and translucent thermoplastic lightweight general-purpose plastic. Polypropylene has chemical resistance, heat resistance, electrical insulation, high strength mechanical properties and good wear-resistant processing performance, which makes it widely developed and applied in many fields such as machinery, automobile, electronic and electrical appliances, construction, textile, packaging, agriculture, forestry, fishery and food industry since its birth. In recent years, with the rapid development of China’s packaging, electronics, automotive and other industries, it has greatly promoted the development of China’s industry. And because of its plasticity, polypropylene materials are gradually replacing wood products, and the mechanical functions of metals have been gradually replaced by high strength, toughness and high wear resistance. In addition, polypropylene has good graft and composite functions, and has a huge application space in concrete, textile, packaging, agriculture, forestry and fishery.
Development History
In 1954, G. Natta first polymerized propylene to polypropylene (using aluminum titanium chloride as catalyst), and founded the theory of directional polymerization, which attracted people’s attention.
In 1957, Italy’s Monte Cartini Company and America’s Hecules Company established 6000t/a and 9000t/a polypropylene production units respectively
From the late 1960s to the mid 1970s, polypropylene entered a period of great development.
Since the 1980s, the output of polypropylene has been in the forefront of synthetic resin.