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The Catalytic Synthesis of Wholly Aromatic Polyesters Based on 4-hydroxybenzoic Acid via Direct Esterification

The synthesis and properties of wholly aromatic polyesters are of considerable practical importance to create functional and high-performance materials. In the present study, by means of catalytic polyesterification using titanium (IV) butoxide, we’ve synthesized wholly aromatic oligomers derived from 4-hydroxybenzoic acid (HBA), aromatic diacids and dibasic phenols. As revealed by FTIR measurements, the average molecular weight of oligomers has varied from 500 to 1400. The results of DSC have shown endotherm peaks attributed to a phase transition of low-molecular oligomers from crystalline state to mesophase and further isotropization. The synthesized oligomers were resistant to high temperatures up to about 300-320 °C.