|Studies on Nanostructures in Rubber
SRI Research & Development Ltd. Tsutsui-cho, Chuo-ku, Kobe, Japan
Nippon Gomu Kyokaishi,(2007),80(3),86-92 General Review in Japanese
The behavior of polymer and filler in stretched rubber has been studied. Using SPM (scanning probe microscopy) and TEM (transmission electron microscopy), it was found that rubber disobeys the assumption of “affine deformation” in nano-scale.
The result of ESR (electron spin resonance) study suggests that chain scission of polymer under stretching occurs mainly at the interface between polymer and filler. From solid-state 13C NMR (nuclear magnetic resonance) study of elongated natural rubber, it was found that the elongation decreased the mobility of the polymer chains and that almost all polymer chains were oriented uniaxially. The polymer/filler interfaces were investigated using EFTEM (energy-filtering transmission electron microscopy).
The distribution of a silane coupling agent around silica in cured rubber can be visualized by elemental maps of silicon and sulfur.
The interfaces between zinc oxide particles and the rubber matrix were also investigated, which show the adsorption of sulfur compounds on the zinc oxide surface. We observed ZnS nanoparticles distributed in rubber matrix for the first time by EFTEM and HAADF-STEM (high-angle annular dark field scanning transmission electron microscopy). This fact indicates that cross-linked rubber have inhomogeneous network structures that may influence the properties. The nanostructures in rubber have been revealed through direct nanoscopic observation.
Elongation, Affine Deformation, SPM, ESR, NMR, EFTEM, Zinc oxide