Continuous Cooling Curve Diagrams of Isotactic-Polypropylene/Polyethylene Blends: Mutual Nucleating Effects under Fast Cooling Conditions

Crystallization kinetics under processing-relevant cooling conditions of polyethylene/isotactic-polypropylene (PE/PP) blends, with compositions similar to real recycled was investigated through an in situ temperature monitoring technique. Continuous Cooling Curve (CCC) diagrams a large crystallization range were obtained for the two phases, thanks new apparatus allowing fast quenching polymer samples. Using this technique, we found “inversion point” order polymers, which arises from difference rates between PP and PE increasing rate. The polymers at low rates, that is, before inversion point, can be tuned by employing non-nucleated or nucleated PP. In particular, crystallizes after above 0.5 °C/s, while solidifies until 80 °C/s. Interestingly, mutual nucleating effects, previously shown only ideal systems such as thin-layered films, interface correlation point. During cooling, phase first enhance onset second lower crystallizing nucleation interface. Ex morphological wide-angle X-ray diffraction experiments confirmed validity results CCC diagrams. Our approach characterize semicrystalline blends facilitates tailoring their properties relevant processing. Moreover, importance knowing controlling type components recycling is demonstrated, given variety behaviors attainable.