Kinetics of orientation of a side-chain liquid–crystal polymer as measured by a high-temperature SQUID-magnetometer

A superconducting quantum interference device (SQUID) magnetometer suitable for measurements of the magnetic susceptibility up to 600 K has been used to follow the kinetics of realignment in the nematic phase of a side-chain liquid–crystal polymer. Experiments are performed using monodomain and polydomain samples. Results obtained in monodomain samples are in quantitative agreement with the prediction of the continuum theory up to an angle of approximately 60°. Experiments conducted at higher starting angles give clear indication of backflow effects. Data obtained from experiments on polydomain samples have been compared with model calculations using the data on the monodomain samples. This comparison leads to the conclusion that in this case backflow effects play an important role, too. All results show that SQUID magnetometry allows monitoring of the kinetics of realignment with highest precision. © 1992 John Wiley & Sons, Inc.