Liquid crystallization of poly(styrene-co-maleic anhydride) induced by intermolecular hydrogen bonds

✍ Scribed by Hua Yan; Xia Zhu

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 233 KB
• Volume: 74
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19991003)74:1<97::aid-app11>3.0.co;2-h

✦ Synopsis

The liquid crystallization of general polymer (GP) with maleic anhydride in the main chain has been realized through molecular recognition and self-assembly based on intermolecular hydrogen bonds. Poly[styrene-co-(N-4-carboxylphenyl)maleimide] (SMIBA) was synthesized by imidization and dehydration of Poly(styrene-co-maleic anhydride) (SMA) with p-aminobenzoic acid (ABA) for use as an H-bonded donor polymer. 4-Methoxy-4Ј-stilbazole (MSZ) and 4-nitro-4Ј-stilbazole (SZNO 2 ) were prepared as an H-bonded acceptor. SMIBA was complexed with MSZ or SZNO 2 by slow evaporation from pyridine solution to form a self-assembly, which exhibits the mesophase, while neither of the individual components is mesogenic. The phase diagrams of a variety of mixtures between of SMIBA and stilbazoles have been established using DSC and POM. They show complete miscibility and high thermal stability of the liquid crystalline phase over the whole composition range. The tuning of liquid crystalline properties was achieved by changing the composition of the mixture and involving it with a mixture of SZNO 2 and MSZ. IR measurements strongly support the existence of an H-bonded complex between the carboxylic acid of SMIBA and the pyridine group of stibazoles. Unlike conventional side-chain liquid crystalline polymer (SLCP), supramolecular SLCP with a lower molecular weigh polymeric donor has higher thermal stability of the liquid crystalline phase due to the microphase separated in the hydrogen bonding case. Liquid crystallization of GP, such as SMA, induced by hydrogen bonds, offers a new route to prepare functional material with controlled molecular architecture from readily accessible and simpler precursors.