Recyclability of In Situ Microfibrillar Poly(ethylene terephthalate)/High-Density Polyethylene Blends

Abstract Repetitive processing was employed to assess the recyclability of in situ microfibrillar poly(ethylene terephthalate) (PET)/high‐density polyethylene (HDPE) blends which were fabricated through a “rectangular slit die extrusion–hot stretching–quenching” process. For comparison, the conventional PET/HDPE blends were also obtained using the same processing operation but without hot stretching. The morphological observation indicated that slit die extrusion and hot stretching successfully made the dispersed PET phase deform in situ into well‐defined microfibrils. The average diameter of the microfibrils increased with the processing cycles. The rheological properties obtained from the parallel‐plate dynamic rheometer suggested that the microfibrillar blends have higher viscosity and viscoelastic moduli (storage and loss moduli) as well as better flow stability than the conventional PET/HDPE blend. More importantly, with the increase in the processing cycles, an increase in yield strength and unchanged tensile modulus were observed for in situ microfibrillar blends, while a decrease in these properties for conventional blend, indicating that the in situ microfibrillar PET/HDPE blends have promising recycling potential. magnified image