Thermotropic copolyesters modified with nonmesogenic rigid groups

• Published in: Polymer bulletin (Berlin, Germany) Vol. 24; no. 3; pp. 293 - 297
• Main Authors: HONG-BING TSAI, CHYUN LEE, NIEN-SHI CHANG, TEH HU, A
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.09.1990; Berlin; New York, NY
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts; Differential scanning calorimetry; Property composition relationship; Sebacate copolymer; Thermotropic state; Condensation polymerization; Liquid crystals; Phase transitions; Hydroquinone; Sebacate polymer; Bisphenol A; Ester copolymer; Optical texture; Preparation
• ISSN: 0170-0839; 1436-2449
• DOI: 10.1007/BF00306577

Two series of copolyesters of sebacic acid, 4,4'-biphenol and a nonmesogenic rigid diol which was either bisphenol A (BPA series) or hydroquinone (HQ series) were prepared by melt polycondensation. Thermal transitions and melt birefringence were investigated by DSC and polarized microscopy respectively. The homopolyester of 4,4-biphenol and sebacic acid (PB8) was found to show two transition temperatures, corresponding to T sub m and T sub i respectively. For the BPA series, the incorporation of amorphous bisphenol A units by copolymerization decreased both T sub m and T sub i and completely destroyed the mesophase when the content of bisphenol A unit was over 50 mol%. For the HQ series, the incorporation of crystalline hydroquinone units decreased T sub m to a greater extent, but decreased T sub i to a lesser extent as compared to the BPA series. When the hydroquinone unit content reaches 80 mol%, the mesophase was completely destroyed. Graphs. 6 ref.--AA