English Abstract

Remarkable Progress in Self-reinforcement of Elastomers Generated Through Strain-induced Crystallization (Part 1);gMacroscopic Inhomogeneity in Cross-linked Rubbers Proved by the Newest Observationh

Yoshihide FUKAHORI
Department of Materials Science, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
Nippon Gomu Kyokaishi,(2011),84(6),189-196 General Review in Japanese

The newest observation disclosed the clear image of macroscopic inhomogeneous structures of cross-linked rubbers.
Cross-linking agent, sulfur disperses as a bulky ZnS in rubber matrix quite inhomogeneously, which generates the heterogeneous phase separation of cross-linked (about 30%) and uncross-linked (about 70%) phases during vulcanization.
The mechanically fundamental units of the cross-linked and the uncross-linked phase are 1~2 μ m and a few hundred nm, respectively. The soft uncross-linked phase surrounding the hard cross-linked phase mainly extends in external extension and swelling, thus the system deforms ununiformly, i.e. non-affinly. The above observation seems to support the models proposed by the author.

Keywords: Inhomogeneous Phase Separation, Cross-linked Rubber, Cross-linked Phase, Uncross-linked Phase, Non-Affine Deformation, Author's Model