Thermal and mechanical properties of binary blends of polypropylene (PP) with a statistical copolymer (85 wt% propylene and 15 wt% ethylene, abbreviated here as VM) have been investigated. Both components were found to be miscible in the melt in the whole range of compositions. No separate domains of VM have been detected by polarizing optical microscopy, and the size of spherulites is going down with increasing VM content. The crystallization temperature of PP as detected by DSC, is going down to 83°C, for PP/VM blends 10:90. This is another evidence for miscibility in the melt. Viscoelastic properties of the melt were measured. Regarding the solid state, the melting enthalpy is exactly proportional to the PP content in the blend. The DSC step height at the glass transition is exactly proportional to the VM content. These results are suggesting a three‐phase model (crystalline, rigid amorphous, and mobile amorphous phase), where the VM component is mainly located in the mobile amorphous regions, while the amorphous part of PP is in the rigid amorphous regions. Stress–strain curves show a systematic increase of elongation at break with increasing VM%, to be extended from 7.8% to more than 550%.

Ternary blends of polypropylene (PP), high-density polyethylene (HDPE), and a random copolymer with 85% propylene and 15% ethylene (trade name Vistamaxx 6202, abbreviated here as VM) have been investigated to elucidate the efficiency of this additive in the management of recycling streams. Differential scanning calorimetry showed that VM will induce simultaneous crystallization of PP and HDPE. Polarized Optical Microscopy revealed a breakdown in the spherulitic structure already at 10% of additive (for blends with ratio PP: HDPE = 1:1), respectively 17%, (for PP/HDPE = 7:3). A similar threshold was found in the impact strength, and stress-strain-curves. This means that VM is also advantageous for recycling of PP: HDPE blends, especially those with high PP content.