English Abstract
Carbon Black Reinforcement of Rubbers No.8 (Final):
The Origin of Weakness and Reinforcement of Elastomers
Yoshihide FUKAHORI
Polymer Engineering Design
Nippon Gomu Kyokaishi,(2005),78(1),19-25 General Review in Japanese

The author proposes the universal model for the cross-linked structure of real rubber vulcanizates, characterized by the heterogeneous networks of a densely cross-linked and a non-cross-linked phase, the volume fraction being 7580% in the former and 2025% in the latter. Fundamentally, the densely cross-linked phase is discontinuously structured in the system, surrounded by the continuous non-cross-linked phase.
If we will accept the above concept, we should carefully reconsider the applicability of the rubber elasticity theory(Gaussian or non-Gaussian)based on the assumption of homogeneous cross-linking to real rubber vulcanizates, concerning the affine deformation, the stress-strain relation, the visco-elasticity and the fracture of rubbers.
In this final report, we would like to summarize the origin of the strength and weakness of rubbers, spreading rubber species to thermoplastic and thermosetting elastomers and polyurethane.

Heterogeneously cross-linked network, Rubber elasticity theory, Thermoplastic elastomer, Thermosetting elastomer, Polyurethane.