Molecular motion and orientation distributions in melt-processed, fully aromatic liquid crystalline polyesters from 1H NMR.
Fully-aromatic thermotropic liquid crystalline polymers (LCP) containing 4-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthoic acid (HNA) were studied with 1H NMR. A two- or three-parameter nematic director distribution in molten or nearly molten samples was obtained via rigorous simulation of wideline spectral lineshapes. This methodology was further employed to yield the chain director distribution in macroscopic sections derived from a frozen contraction flow. In addition, the dynamic conformation of polymer chains through the melting transition was monitored via lineshape analysis of samples having (bulk) isotropic director distributions. Extension of rigorous 1H NMR spectral deconvolution to recently developed solid-state NMR imaging sequences is discussed.
Gentzler
M
M
Center for Advanced Materials, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
Patil
S
S
Reimer
J A
JA
Denn
M M
MM
D003460:Crystallization; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008968:Molecular Conformation; D009038:Motion; D011091:Polyesters / Q000737:chemistry*; D011522:Protons
D006841:Hydrocarbons, Aromatic; D011091:Polyesters; D011522:Protons