SYNTHESIS AND PROPERTIES OF POLY(ETHER IMIDE)S DERIVED FROM DIHYDROXYNAPHTHALENES

Poly(ether imide)s were synthesized from bis(ether anhydride)s derived from 1,5-, 2,3-, 2,6- and 2,7-dihydroxynaphthalenes and various aroma tic diamines using a two-stage solution process, normally with chemica l imidization. During the synthesis of polymers from the bis(ether anh ydride) from 2,3-dihydroxynaphthalene and 4,4'-oxydianiline (4,4'-ODA) , by both chemical and thermal imidization, small proportions of a rel atively insoluble, infusible, crystalline solid were produced. It is p roposed that this product is a cyclic oligomer. Solubilities of the po lymers were assessed and, where sufficiently soluble, molecular weight s were determined by gel permeation chromatography. Apart from polymer s based on 2,3-naphthalene units, the polymers had limited solubilitie s. Glass-transition temperatures were determined; all were in excess o f 220 degrees C, some were in excess of 300 degrees C. Several poly(et her imide)s based on ODA, were found to be thermally stable to 590 deg rees C. Polymers based on the bis(ether anhydride) derived from 2,3-di hydroxynaphthalene gave strong solvent-cast films with high moduli ext ensions to break were modest except for the polymer from the diamine B APB which extended to 150% prior to fracture.