Study of the conformational disorder in polyesters giving liquid-crystalline phases

✍ Scribed by Beniamino Pirozzi; Roberto Napolitano; Angela Tuzi; Roberto Centore

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 715 KB
• Volume: 6
• Category: Article
• ISSN: 1022-1344
• DOI: 10.1002/mats.1997.040060408

✦ Synopsis

Abstract

Conformational and packing energy analyses have been performed by molecular mechanics calculations on the polyester derived from the condensation of 2‐(4‐hydroxyphenyl)‐6‐hydroxybenzoxazole with terephthalic acid, which presents a high degree of crystallinity in spite of the head‐to‐tail constitutional disorder. The line repetition groups in accordance with the experimental value of the c axis have been taken into account. Possible conformations of chains having constitutional and conformational disorder in the crystalline phase have been proposed. Packing energy calculations performed on pairs of chains give the close packing distances and indicate the best symmetry elements. The results are in agreement with the unit cell obtained by X‐ray data, the thermodynamical properties of the polymer and the existence of liquid‐crystal phases.