Synthesis and properties of aromatic copolyesters with a ionic liquid
발표자
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초록
내용
A series of aromatic copolyesters containing pyrrolidinium/piperidinium cations with PF6- or Tf2N- counter-anions are successfully synthesized from terephthaloyl chloride, N,N'-dihydroxylalkyl pyrrolidinium/piperidinium ionic liquids (ILs) and an aromatic comonomer, BPA di(2-hydroxyethyl)ether (BDHE). The various copolyesters are prepared from changing the mole ratio of the two dihydroxy monomers, pyrrolidinium/piperidinium IL and BDHE, and the existence of the comonomers are confirmed by 1H NMR. Thermal stabilities of the synthesized copolyesters are investigated by TGA and they are stable up to 300 oC. During the 2nd heating scan of DSC, only a Tg is shown, from which all the copolyesters are amorphous and no crystalline morphology is found. As the ratio of BDHE is higher, Tg is increased, because of the more rigid aromatic units in the polymer backbone. Ionic conductivities with different temperatures are measured. Pyrrolidinium-C11 Tf2N- polyester shows highest ionic conductivity.