Shu-Jen Han, Dharmendar Reddy, et al.
ACS Nano
A cyclic poly(aryl ether phenylquinoxaline) was prepared via the self-polymerization of 1 in an N-methyl-2-pyrrolidone (NMP) solution containing base using a pseudo-high dilution polymerization condition. The macrocycle 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 azeotrope with toluene 170°C. A concentrated solution of the macrocycle was added to the reaction mixture over an 8 hour period. The reaction was allowed to proceed for an additional 24h to ensure quantitative reaction. A number of characterization techniques were used to study the cyclization of 1 including GPC, HPLC, H NMR and matrix-assisted laser desorption ionization (MALDI) mass spectroscopy. The MALDI-TOF mass spectrum of the cyclization of 1 clearly showed that a mixture of macrocycles is obtained, with the expected distribution of molecular weights. Facile ring opening polymerization of the cyclic poly(aryl ether phenylquinoxaline) oligomers was accomplished with a nucleophilic initiator. High polymer was obtained for each polymerization temperature (η =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 the high molecular weight linear analog (250°C).
Shu-Jen Han, Dharmendar Reddy, et al.
ACS Nano
T.N. Morgan
Semiconductor Science and Technology
William Hinsberg, Joy Cheng, et al.
SPIE Advanced Lithography 2010
John G. Long, Peter C. Searson, et al.
JES