Cyclic oligomers for production of linear polyketones, polyphthalazines and polyisoquinolines

摘要

Low molecular weight cyclic oligomers of formula (I) ##STR1## in which n is an integer of 2 to 20, and each C in the oligomer is a radical of formula (II): ##STR2## and each X in the oligomer is --O--R--O- - or --S-- R--S--, B and D are both carbonyl groups CO, or together represent a divalent radical of formula ##STR3## in which A.sub.1, A.sub. 2, A.sub.3 A. sub.4, Ar.sub.1, Ar.sub.2 and Ar.sub.3 are selected from a variety of aromatic radicals, A.sub.1, A.sub.2, Ar.sub.3 and Ar.sub.4 also possibly being hydrogen, are useful in the production of high molecular weight, linear, polyketones, polyphthalazines and polyisoquinolines; the cyclic oligomers have low melt viscosities when heated above their softening temperatures and can be readily molded, whereafter they can be ring-open polymerized to form molded high molecular weight polymer products with excellent properties.