| 초록 |
Thermotropic liquid crystalline polyesters (TLCPs) have been extensively used due to their excellent thermal resistance, mechanical strength, and chemical resistance. However, aromatic TLCPs are difficult to process due to their high melting temperature. To overcome these shortcomings, the melting temperature of TLCPs needs to be lowered by introducing kinked structures, aliphatic or flexible units, or nonlinear monomers. A 2,5-thiophene unit is a heterocyclic aromatic moiety with a nonlinear structure, which can reduce the melting temperature. In this study, a series of novel TLCPs were synthesized by melt polycondensation of 4-hydroxybenzoic acid, 2,5-thiophenedicarboxylic acid, and 4,4’-biphenol with various compositions. The chemical structure, crystalline feature, and morphology of the synthesized TLCPs were characterized with FT-IR, XRD, SEM, and POM. The thermal transition, thermal stability, and mechanical properties were analyzed using DSC, TGA, and DMA. |
