1, polypropylene is a polymer formed by addition polymerization of propylene. It is a white waxy substance with a transparent and light appearance. The chemical formula is (C3H6)n, the density is 0.89 ~ 0.9 1g/cm3, it is flammable, the melting point is 189℃, it softens at about 155℃, and the service 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 equipment, automobiles, bicycles, parts, transportation pipelines, chemical containers and so on. It is also used for the packaging of food and medicine.

2. Polypropylene, abbreviated as PP, is a colorless, odorless, nontoxic and translucent solid substance. Polypropylene is a kind of thermoplastic synthetic resin with excellent performance, and it is a colorless and translucent thermoplastic lightweight general plastic. Polypropylene has chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good wear-resistant processability, and has been widely developed and applied in the fields of machinery, automobiles, electronic appliances, construction, textiles, packaging, agriculture, forestry, fisheries and food industry. In recent years, with the rapid development of China's packaging, electronics, automobile and other industries, it has greatly promoted the development of China's industry. Moreover, polypropylene material is gradually replacing wood products because of its strong plasticity, and its high strength, toughness and wear resistance are gradually replacing the mechanical functions of metals. In addition, polypropylene has good grafting and compounding functions, and has great application space in concrete, textile, packaging, agriculture, forestry and fishery.