Molecular mobility and strengthening of oriented liquid-crystal polymers

Broad-line proton magnetic resonance has been used to study cooperative mesophase molecular motion in the example of a fully-aromatic oriented liquid-crystal polymer Vectra A950. The molecular mobility is found to decrease as a result of heat treatment, which is considered to be the reason for a higher tensile (rupture) strength owing to an increase in the activation energy for the fracture process. Fiz. Tverd. Tela (St. Petersburg) 41, 859–861 (May 1999)