Novel Trends in Ladder Polyheteroarylenes

Development of several fields of modern engineering has generated a need for the preparation of polymeric materials with working temperatures as high as 300°C. The solution of this problem is largely connected with preparation of new thermally stable polymers. As a consequence, beginning in the middle of the fifties, numerous investigations were carried out in order to obtain new thermally stable macromolecular compounds 1]. These investigations resulted in a considerable number of organo-element 1] and aromatic carbo-chain polymers 1] with a complex of valuable properties; but the chemistry of aromatic polymers containing various heterocycles in the main chains of macromolecules, so-called polyheteroarylenes, has received the most development 1].