Polypropylene is a polymer obtained by addition polymerization of propylene. It is a white waxy material with transparent and light appearance. The chemical formula is (C3H6) n, the density is 0.89 ~ 0.91g/cm3, [1] is flammable, the melting point is 189 ° C, and it softens at about 155 ° C. The use temperature range is - 30 ~ 140 ° C [2]. It can resist the corrosion of acid, alkali, salt solution and various organic solvents below 80 °C, and decompose under high temperature and oxidation. Polypropylene is widely used in the production of fiber products such as clothing, blankets, medical devices, automobiles, bicycles, parts, conveying pipes, chemical containers, etc. it is also used in the packaging of food and drugs
