Evaluation of Mechanical Properties of Carbon Black Reinforced Natural Rubber by Atomic Force Microscopy

Abstract

Atomic force microscopy (AFM) has an advantage of obtaining topographic and mechanical properties at the same time. In analyzing the force-distance curve using Hertz theory, Young's modulus is obtained with nanometer-scale resolution. Furthermore, sample deformation by the force exerted is also estimated from the force-distance curve analysis. We can reconstruct a real topographic image by incorporating apparent height with deformation image. We applied this method for obtaining information on mechanical properties of carbon black reinforced natural rubber. We were able to obtain Young's modulus distribution image together with apparent topographic and reconstructed real topographic images. Then we were able to recognize three regions; rubber, carbon black (or bound rubber) and interfacial regions. Though the existence of these regions had been investigated by pulsed nuclear magnetic resonance, this paper would be the first report on the quantitative evaluation of the interfacial region in real space.