English Abstract
Study of Thermoplastic Gels Having a Micro-Cellular Porous Structure and Their Potential on Industrial Applications
Naruhiko MASHITA1), Xiaorong WANG2)
1) Bridgestone Corp. Chemical and industrial products materials development department. Yokohama-shi, Kanagawa-ken, JAPAN.
2) Bridgestone Americas Center for Research and Technology. 1200 Firestone Parkway Akron, OH 44317 USA.
Nippon Gomu Kyokaishi,(2005),78(4),147-152 General Review in Japanese

Novel non-aqueous physical gels based on a small amount of semi-crystalline thermoplastic elastomers and a large amount of oils of low molecular weight were studied. Morphological investigation of the gels by means of X-ray CT confirmed that the gels had three-dimensionally continuous polymer cells. We name this a "Microcellular Porous Structure". The network structure was formed by the phase separation of a homogeneous mixture of TPE/oil. It was observed that modulated structure due to spinodal like decomposition appeared in the initial stage of the phase separation; however, the modulated structure changed to the clear network structure of polymer-rich phase and clusters of spherical oil-rich phase in the late stage. Time evolution of the size D of a typical structure during the phase separation process at a constant temperature was estimated as in the initial stage and in the late stage. Industrial potentials of the gels and/or its super-structure were introduced.
A cushion for medical and welfare use, a soft damping material made of physical gel and comb-like polymer for wide service temperature ranges, and thin film or coating having network structure were introduced.

Thermoplastic elastomer, Physical gel, Morphology, X-ray CT, Spinodal decomposition.