A study of liquid crystalline poly- p-methacryloyloxy- p-azobenzenes

Abstract

The conformational properties of thermotropic liquid crystalline polymers having the side mesogenic groups poly- p-methacryloyloxy- p-n-amyloxyazobenzene and poly- p-methacryloyloxy- p-ethylazobenzene and their corresponding monomers are studied by IR spectroscopy. As in the polymers, so in the monomers also, in the solid phase, conformational transformations associated with rotational isomerism in the ester group and p-alkoxy fragment are observed. In poly- p-methacryloyloxy- p-n-amyloxyazobenzene the conformational changes in these groups take place separately, and in the corresponding monomer simultaneously 12°C before the melting point T mp and precede polymerization of the monomer in the solid phase close to T mp. It is established that in polymer films in the glass-like state the conformational transformations are accompanied by an increase in the degree of homeotropic orientation with increased temperature.