Improved Properties of Metallocene Polyethylene/Poly(ethylene terephthalate) Blends Processed by an Innovative Eccentric Rotor Extruder

In this investigation, metallocene polyethylene (m-PE) was melt blended with poly(ethylene terephthalate) (PET) with an effort to achieve improved mechanical properties using a novel eccentric rotor extruder (ERE) without the addition of any compatibilizers. The phase morphology, rheological properties, crystallization behavior, and mechanical properties of the fabricated blends were carefully studied to explore the effect of the elongational flow field on the dispersion and mixing of PET in the m-PE matrix and the interface of the two immiscible polymers. For comparison, a conventional twin-screw extruder (TSE) was used to prepare the same blends as references using the same processing condition. It shows that the elongational flow field in ERE is much more effective to disperse the immiscible PET in the m-PE matrix with a smaller particle size and a narrower particle size distribution, compared to the shear flow field in TSE. A compatibilizer, ethylene-co-methyl acrylate-co-glycidyl methacrylate (E-MA-GMA), was added to the m-PE/PET blends during the processing using TSE and ERE. It was observed that the improvement of the tensile property by adding the compatibilizer is marginal for the m-PE/PET blends processed using ERE, which indirectly proves the high effectiveness of the elongational flow field on the enhancement of the dispersion and mixing of PET in the m-PE matrix and the interface interaction.

In Situ Reactive Interfacial Compatibilization of Poly(Ethylene Terephthalate)/Metallocene Polyethylene Blends

Poly (ethylene terephthalate) (PET) was melt blended with metallocene polyethylene (m-PE) with an effort to achieve excellent mechanical properties, a terpolymer elastomer, ethylene-methyl acrylate-glycidyl methacrylate (E-MA-GMA), was loaded as compatibilizer through in situ reacting with the end groups of PET to bond two immiscible phases. In order to investigate the in situ effects of the compatibilizer, scanning electron microscopy (SEM) and mechanical analysis was applied to investigate PET/m-PE blends’ properties along with the variation of compatibilizer content. Statistics of particle size were applied to demonstrate the variation of the blends’ properties along with morphology. The results revealed that an appropriate loading of compatibilizer can obtain stiffness-toughness balanced blends.