Compatibilization of polypropylene/high‐density polyethylene blends using poly(propylene‐co‐ethylene)

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.