MECHANISTIC INVESTIGATION OF THE PREPARATION OF POLYMER CERAMIC NANOCOMPOSITES/

Polyimide/aluminum nitride (AIN) nanocomposites with very high packing density were obtained through an efficient solution mixing method. Th e homogeneous composites showed a trend of decreasing thermal expansio n, and increasing hardness and Young's modulus, as the ceramic loading increased. A detailed investigation of the preparation process, via i n-situ FT-IR analysis of a series of probe molecule reactions on the p article surface, suggested a strong chemisorption of amide groups on t he nanoparticle surface. Therefore, a reaction mechanism for the chemi sorption is proposed. Considering the structural similarity of the pro be molecules and poly(amic acid), a precursor to polyimide, indication s are that (I)chemisorption plays an important role for mixing process ing of a nanoparticle/organic medium; and (2) amide group adsorption i s one of the most efficient interaction during the suspension processi ng for the chemically synthesized nanostructured AlN powders. (C) 1997 Acta Metallurgica Inc.