Thermal and Mechanical Properties of PET/PEN-FBPE Copolymers Containing Fluorenylidenebis(2-phenoxyethanol)

Abstract

PET/PEN-FBPE copolymers containing fluorenylidene bis(2-phenoxyethanol) (FBPE) were prepared with various FBPE concentrations. The concentration of PEN in PET/PEN copolymer was fixed at 8 mol%. The glass transition temperature of copolymer was increased from 72 degrees C for PET/PEN copolymer to 117 degrees C for PET/PEN-FBPE copolymer containing 20 mol% of FBPE. The thermal decomposition temperature of copolymer measured at 5 wt% loss was increased from 369 degrees C for PET/PEN copolymer to 423 degrees C for PET/PEN-FBPE copolymer containing 20 mol% of FBPE. Also, the heat deflection temperature was increased from 66 to 105 degrees C with FBPE concentration. The impact strength was also increased from 6.2 to 10.5 J/m with increasing FBPE concentration. The effect of FBPE on the tensile modulus was not observed, but the tensile strength increased from 51 to 74 MPa at 20 mol% loading of FBPE. The optical transparency of copolymer was slightly decreased from 90 to 87% with increasing FBPE concentration.