Synthesis and Liquid Crystal Properties of Supramolecular Side-Chain Liquid-Crystalline Polymers Containing Poly(acrylic acid) Intermolecular Hydrogen Bonds

Abstract

Novel supramolecular side-chain liquid-crystalline polymers were prepared from poly(acrylic acid) (PAA) and pyridyl Schiff base derivatives through intermolecular hydrogen-bonding interaction between PAA and nitrogen of pyridyl Schiff base derivatives. PAA used as H-bond donor. Pyridyl Schiff base derivatives used as H-bond acceptors. The existence of H-bonding was confirmed by FT-IR spectroscopy. Polymer complexes exhibited stable thermotropic mesophase. Differential scanning calorimetry, polarized optical microscopy, and X-ray diffraction measurements were used to investigate LC behavior. The complexes exhibited smectic C phase broken-fan shaped texture. On increasing spacer length of substituent, the clearing temperature range of the mesophase increased.

Keywords:

• Liquid crystal
• mesogen
• self-assembly
• smectic
• thermal properties

Funding

The authors acknowledge the financial support from Council of Scientific and Industrial Research (CSIR F. No. 01(2310)/09/EMR II), New Delhi, India.