Polypropylene (PP) is one of the commodity polymers used in large quantities because of its very advantageous price/performance ratio. The low glass-transition temperature (Tg) of polypropylene at about 0
oC was limiting the application range and practically prevented application in subzero environments. A whole range of PP/elastomer blends and PP impact copolymers from multireactor processes have been developed to overcome the limited low-temperature impact resistance of polypropylene and allow its wide application areas.
The increasing demand for improving properties pushes the limits of existing property ranges to extreme levels. A unique combination of impact resistance and stiffness of a regular block copolymer with a transparency level of typical random copolymers is often requested by high-performance frozen food packaging and consumer applications.
In this work, the morphology and the properties of a new generation of polypropylene were investigated and compared with polypropylene homopolymer and ethylene/propylene random copolymer modified with different types of elastomers. The amount of dispersed phase (5–20 wt %) and its type was varied, and the influence of different matrix materials was studied by using a polypropylene homopolymer and an ethylene–propylene random copolymer. The results clearly demonstrate the possibility to achieve good low temperature impact strength together with a good transparency in ternary systems.
