Synthesis and properties of an aluminum nitride/polyimide nanocomposite prepared by a nonaqueous suspension process

A nanocomposite of a chemically synthesized nanostructured aluminum nitride (AlN) and a polyimide has been studied. Using a nonaqueous polar solvent,N-methylpyrrolidinone (NMP), as the suspension media, the degree of particle agglomeration of AlN was reduced dramatically from micron to nanoscale size. Upon the addition of poly(amic acid) to the AlN/NMP suspension, a further deagglomeration of the particles was observed. The surface physicochemical interactions have been investigated by characteristic model reactions using FTIR spectroscopy. A mechanistic interpretation for the deagglomeration and stabilization behavior is discussed. The formation of the AlN/PI nanocomposite was achieved by the rapid solidification of the precursor suspension followed by compression molding. Such an approach for nanocomposites exhibits better homogeneity with ultrafine fillers and allows a tailorable composition and property at the nanoscale level. Finally, AlN/PI nanocomposites with an increased ceramic loading, up to 65% by volume, were attained and their thermal and mechanical properties, along with the compositional effects, have been investigated.