POLY(ARYL ETHER PHENYLQUINOXALINES) VIA ANIONIC RING-OPENING POLYMERIZATION OF MACROCYCLES

A cyclic poly(aryl ether phenylquinoxaline) was prepared via the self- polymerization of 1 in an N-methyl-2-pyrrolidone (NMP) solution contai ning base using a pseudo-high dilution polymerization condition. The m acrocycle formation of 1. was carried out in the presence of potassium carbonate in a NMP/toluene solvent mixture at a solids content of 1%. The water generated by phenoxide formation was removed as an azeotrop e with toluene 170 degrees C. A concentrated solution of the macrocycl e was added to the reaction mixture over an 8 hour period. The reactio n was allowed to proceed for an additional 24h to ensure quantitative reaction. A number of characterization techniques were used to study t he cyclization of 1 including GPC, HPLC, H NMR and matrix-assisted las er desorption ionization (MALDI) mass spectroscopy. The MALDI-TOF mass spectrum of the cyclization of 1 clearly showed that a mixture of mac rocycles is obtained, with the expected distribution of molecular weig hts. Facile ring opening polymerization of the cyclic poly(aryl ether phenylquinoxaline) oligomers was accomplished with a nucleophilic init iator. High polymer was obtained for each polymerization temperature ( eta=0.4-0.5 dl/g in NMP), however, prolonged reaction time resulted in significant gel formation. The Tg's were high and commensurate with t he high molecular weight linear analog (250 degrees C).