Polypropylene is the world’s second most widely used thermoplastic after polyethylene. It is produced by the polymerization of propylene. Polypropylene is used mainly for molding, filaments, fibers and films and is widely used to make molded containers and cars.
There are three main grades of polypropylene resin allowing for changes in specific properties as determined by the composition of the polymer chain.
Polypropylene homopolymers are thermoplastic resins produced through the polymerization of propylene with catalysts. The homopolymers can be used in different processing technologies, such as blow moulding, injection moulding, film, sheet extrusion and thermoforming. Homopolymers provide a broad set of properties to meet market needs in packaging, household goods, textiles, film, healthcare, and pipe as well as applications in the automotive and electrical industries.
Polypropylene random copolymers are thermoplastic resins produced through the polymerization of propylene, with ethylene or butene bonds introduced in the polymer chain. These resins provide a broad range of characteristics and are used in a wide range of applications such as high transparency packaging, blow moulding and injection moulding.
Polypropylene impact copolymers are thermoplastic resins derived through copolymerization with ethylene, but with this grade the ethylene content is much higher than with random copolymers. This results in a much tougher material with excellent impact strength even at low temperatures.