Structural effects on the mesomorphic behaviour of thermotropic liquid crystal poly(ester β-sulphide)s

✍ Scribed by Giancarlo Galli; Emo Chiellini; Michele Laus; Annino S. Angeloni

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 414 KB
• Volume: 27
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(91)90099-a

✦ Synopsis

Al~ract--Three new classes of thermotropic liquid-crystalline poly(ester fl-sulphide)s C7Sn, C8Sn and C10Sn were prepared, based on alkylene spaced (m = 7, 8 or 10) p-oxybenzoyl diads interconnected by bis-sulphide containing spacer segments (n = 2-6). A nematic mesophase is exhibited in each case, with stability and persistence depending on the length and parity of both flexible segments. The nematicisotropic transition parameters are discussed with reference also to those of previously investigated poly(ester fl-sulphide)s C5Sn and C9Sn to elucidate the effects of structural variations on the thermotropic properties of the polymers. The sequence aromatic-aliphatic-aromatic in poly(ester fl-sulphide)s CmSn should be regarded as the actual mesogenic core regularly interspersed by sulphide-containing flexible segments.