Property evaluation of nanofilled polymers

Interest has grown in recent years on the effects of nanosized fillers on the properties of polymeric systems. In particular, we arc interested in studying the changes in electrical, mechanical, and thermal properties of thermosetting polyimides as coated and uncoated nanosized fillers are added in increasing levels of concentration. The results are compared to micronsized filled polyimides of similar compositions. The electrical conduction of the nanocomposites is found to be thermally assisted ionic in nature. The data shows deeper trapping by the nanofillers. We have also observed interesting changes in % elongation and thermal conductivity while modulus levels do not change significantly. A change in stress state during failure is proposed for the: observed improved mechanical properties. Thermal conductivity of the filled polymer systems seemed to be most affected by a coating on the surface of the nanofillers. Interfacial adhesion and percolation theory is suggested as a possible explanation for the differences