Fractionated Crystallization of High-Density Polyethylene as an Evidence of Dispersed Phase Morphology in PET/HDPE Blends

The fractionated crystallization of HDPE as a dispersed phase in immiscible polymer blends with PET at composition of 15 wt-% was investigated. The dramatic influence of the molecular weight of the HDPE on its melt viscosity and therefore on the dispersion is reflected on the relative intensities of the twin peaks that are observed during the crystallization of the PE phase. The minimum volume of a nucleated domain was found to be in agreement with the typical size of PE spherulites. The effect of the addition of a compatibilizer of the E-GMA type was also studied.