Polypropylene, abbreviated as PP, is a polymer formed by the addition reaction of propylene. It is a white waxy material with a transparent and light appearance. The chemical formula is C3H6n, with a density of 0.89-0.91g/cm3. It is flammable and melted Point at 189 ℃, soften at around 155 ℃, and use at temperatures ranging from -30 to 140 ℃ [2]. It can withstand corrosion from acids, alkalis, salt solutions, and various organic solvents below 80 ℃, and can decompose under high temperature and oxidation.
