Liquid crystalline copolyester made from recycled polyethylene terephthalate and p-acetoxybenzoic acid: synthesis, characterization and blending with recycled polyethylene terephthalate

摘要

In our work, liquid crystalline copolyester (LCC) was synthesized by high temperature polycondensation of recycled polyethylene terephthalate (rPET) and p-acetoxybenzoic acid (ABA) with rPET/ABA molar ratio equal to 40/60 mol％. The structure of synthesized LCC was confirmed by FTIR and XRD methods. Thermal properties of synthesized LCC were characterized using differential scanning calorimetry (DSC). The properties of synthesized LCC were compared to that of commercial PET 40 mol％/ ABA 60 mol％ copolyester. The synthesized LCC was used as a modifier for rPET. Blends with a content of the synthesized LCC equal to 2-10 wt％ were obtained by melt mixing with twin-screw extruder. Mechanical, rheological and calorimetric properties of the blends were investigated. Results showed that addition of small amount of the synthesized LCC (2-5 wt％) enhanced processability as well as increased mechanical properties of rPET.