Synthesis and Characterization of High Molecular Weight PCT Polyester

A series of poly(1, 4-cyclohexylenedimethylene terephthalate) (PCT) with controllable molecular weight was prepared by direct esterification, subsequent polycondensation and molten chain-extending reaction using 1, 4-cyclohexanedimethanol (CHDM), terephthalic acid (PTA), pyromellitic dianhydride (PMDA) and triglycidyl isocyanurate (TGIC) as materials. The molecular structure, thermal and mechanical properties of polymers were characterized by Fourier Transform Infrared Spectrum (FT-IR), Gel Permeation Chromatograph (GPC), Differential Scanning Calorimetry (DSC), Thermal Gravity (TG) analysis, Wide Angle X-ray Diffraction (WAXD) and electronic universal testing machine. Results showed that when n(CHDM):n(PTA) was 1.2, and combined catalysts including tetrabutyl titanate (TBT), germanium dioxide (GeO₂), antimony trioxide (Sb₂O₃) (0.1 mg/g) and cobalt acetate (Co(Ac)₂) (0.05 mg/g), reaction 3 h at 290℃, the intrinsic viscosity of PCT was 0.560 dL/g. Then the product was used to react with combination chain-extend agent of PMDA-TGIC, which had the intrinsic viscosity 0.680 dL/g. The films of PCT and chain-extend PCT had excellent mechanical property.