Nmr Studies on Side Chain Mesomorphic Polymers

Abstract

Nine polymers with general formula of

were investigated by high resolution ¹H and ¹³C NMR spectroscopy in solution. The absorption lines were ass igned. It was concluded from the line broadening tha[tbar] the mobility of the atoms in the main chain decreased when the aromatic cores were bonded to the main chain without spacer, but did not depend on the length of the spacer, The atomic mobilities increase with the distance from the main chain.

Two polymers with hexyloxy spacer were investigated by high resolution ¹³C-NMR spectroscopy in bulk. The ring-current effect of aromatic carbon atoms in mesomorphic bulk before the isotropisation indicates rather lamin ar structure than a nematic one.

The polymers with hexyloxy spacers contain -CH₂COOCH₂-segments in the main chain resulted two extra lines in ¹H-NMR spectra. The appearence of these segments is ba[sbar]ed on a destructive chain transfer reaction, Thus, the polymers are rather copolymers than homopolymers.

Keywords:

• high resolution NMR
• mesomorphic polymers
• NMR spectra in bulk
• ring-current effect
• destructive chain transfer