This study examined the polymerizations of maleic anhydride in solution and in the bulk phase catalyzed by nanocrystalline titania or sodium acetate. Through IR and H-1-NMR, the monomer and polymer were characterized, and the structure of the polymer was confirmed. Moreover, the polymer molecular weight was measured to be 400-800 in solution and 2000-3000 in the bulk phase. The mechanism of the catalytic polymerization was also investigated. (C) 2003 Wiley Periodicals, Inc.