Synthesis, tensile, and thermal properties of polyimide/diamond nanocomposites

Polyimide/diamond nanocomposites were prepared using 4,4'-diaminoiphenyl ether and 3,3',4,4'-benzophenonetetracarboxylic dianhydride. The structure of the polyimide/diamond nanocomposites was characterized by Fourier transform infrared, ultraviolet and transmission electron microscopy. Agglomeration of nano diamond particles is observed in polyimide matrix as revealed by transmission electron microscopy micrographs which is ascribed to the high surface free energy of particles. Both tensile strength and failure strain of polyimide are obviously enhanced with incorporation of nano diamond particles though tensile modulus only shows slight increase. The reinforcing effect of nano diamond on polyimide is discussed. Thermal stabilities of the polyimide/diamond nanocomposites are evaluated using a thermogravimetric analyzer. The thermal stability of nanocomposites is slightly reduced as indicated by a small decrease in onset degradation temperature.