English Abstract

Loss Tangent Mapping Measured by Nanorheological Atomic Force Microscopy

Eijun UEDA *1 *2
*1:Research & Development Center, Zeon Corporation, Kawasaki, Kanagawa, Japan
*2:Department of Chemical Science and Engineering, Tokyo Institute of Technology, Meguro-ku, Tokyo, Japan
Nippon Gomu Kyokaishi,(2018),91(10),383-387 General Review in Japanese

Atomic force microscopy (AFM) offers nanometer-scale mapping of materials’ properties. Especially our modified AFM called as ‘nanorheological AFM’ enables to measure the accurate frequency-dependent storage modulus, loss modulus, and loss tangent (tanδ) over a wide frequency range from 1.0 Hz to 20 kHz at same temperature, in addition to controlling a wide temperature range from -10 to 30 °C, so that we can undergo the viscoelastic maps of mechanical properties over 6 orders frequency.
In this report, consequently, the values of dynamic properties obtained by nanorheological AFM can be compared with those using bulk dynamic mechanical analysis (DMA) measurements. The peak frequency and values of tanδ obtained for silica-filled styrene-butadiene rubber (SBR) nicely corresponded to those of bulk DMA measurements. The loss tangent mapping and its histogram showed interfacial regions around silica particle has lower loss tangent than that of SBR rubber matrix. We have succeeded in quantitatively measuring the frequency dependence of inhomogeneity in rubber component nearby silica interface for the first time.

Keywords: Nano Palpation Atomic Force Microcopy, Nanorheological Atomic Force Microscopy, Loss Tangent Map, Silica-filled SBR