Polypropylene (PP) is a solid thermoplastic polymer with a melting point of 165-170°C and a density of 900-910 kg/m3. The maximum operating temperature of the PP without load is 150°С. Polypropylene has a higher heat resistance than polyethylene and has good dielectric properties over a wide temperature range. PP is insoluble in organic solvents at room temperature, when heated to 80°C and above, it dissolves in aromatic and chlorinated hydrocarbons. Polypropylene is resistant to acids and bases, as well as to aqueous solutions of salts, mineral and vegetable oils. PP is less susceptible to cracking under the influence of aggressive environments. Various grades of polypropylene modified with mineral fillers and rubbers are produced.