Structure and Properties of r-PET/TPEE/LDPE-g-AA Blends

The blends of recycled poly (ethylene terephthalate) (r-PET)/thermoplastic polyester-ether elastomer (TPEE)/acrylic acid grafted low density polyethylene (LDPE-g-AA) were prepared by extrusion and injection molding. The mechanical, morphological and rheological properties of the blends were investigated by mechanical test, SEM and torque rheometer, respectively. The results show that the Charpy impact strength of the blends increases to the maximum when adding 3 wt % LDPE-g-AA and then decreases with the further increase of LDPE-g-AA contents, while the tensile strength of the blends decreases with the increase of LDPE-g-AA contents. The SEM shows that the particle sizes of TPEE in the blend containing 3wt% LDPE-g-AA become much smaller than that in the uncompatibilized blends, and a more uniform and better islands-in-sea morphology is obtained. Furthermore, the addition of LDPE-g-AA decreases the viscosity of the blends, leading to an overall improvement of processability. From these results above, it can be concluded that the introduction of LDPE-g-AA increases the compatibility and processability of r-PET/TPEE blends effectively.