2. Polypropylene is a thermoplastic resin polymerized from propylene. It is a white waxy substance with a transparent and light appearance. Its density is 0.89 ~ 0.9 1g per cubic centimeter, it is flammable, its melting point is 165℃, it softens at about 155℃, its service temperature is -30 ~ 140℃, and it can resist acids, alkalis and acids below 80℃.
3. Polypropylene can be divided into isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene according to the arrangement position of methyl groups. Widely used in the production of fiber products, medical devices, automobiles, transportation pipelines, chemical containers and so on. It is also used for the packaging of food and medicine.