NOVEL MACROCYCLIC ARYL ETHER OLIGOMERS CONTAINING A DIPHENYLACETYLENEMOIETY - SYNTHESIS, CHARACTERIZATION AND RING-OPENING POLYMERIZATION

An efficient synthetic route to a range of macrocyclic aryl ether keto ne and sulfone oligomers containing a cross-linkable diphenylacetylene moiety in the backbone is described. This new class of macrocyclic ol igomers, obtained in excellent yield, is prepared by an aromatic nucle ophilic substitution reaction from the potassium salt of bis(3-hydroxy phenyl)acetylene and activated difluoro-monomers. Detailed structural characterization of these novel oligomers by the combination of n.m.r. and matrix assisted laser desorption and ionization-time of flight-ma ss spectroscopy (MALDI-TOF-MS) confirms their cyclic nature; and the c ompositions of these macrocyclic oligomers are provided by g.p.c. and reverse-phase gradient h.p.l.c. analyses. MALDI-TOF-MS is a unique too l for the determination and the proof of the cyclic nature of random c o-cyclic oligomers, and also provides answers to the possible combinat ions of monomer units in the cyclic olgiomeric components for the rand om co-cyclic oligomers. All macrocyclic oligomers are semicrystalline with T-m varying from 267 to 370 degrees C and when the oligomers are heated an exothermic reaction, resulting from reaction of the acetylen e units, occurs in the range of 340-470 degrees C and the macrocyclics undergo a cross-linking reaction. Polymerization of the lower melting macrocyclic oligomers at 280-300 degrees C, in the presence of a nucl eophilic initiator, led to the formation of high molecular weight inso luble materials with limited cross-linking reactions taking place. The resulting polymers can be further cross-linked at 340 degrees C with a T-g increase up to 100 degrees C or complete disappearance of T(g)s. Copyright (C) 1996 Elsevier Science Ltd.