1990 Volume 63 Issue 9 Pages 573-584
The change of the physical property values and the stress relaxation due to the phase transition of the dispersed particles structure in SBR vulucanizates, in which the carbon blacks with different reinforcing property and CaCO3 without surface activity were compounded, were investigated.
(1) Particle reinforcing property α is given by the equation in which
α=2.5{1+(1+β)•C*}
the unit volume fration of C phase C* and the restraint parameter β of molecular chain motion were introduced, and the particle reinforcing property α and the volume fraction of particles (Vf)c that the change of the physical property values due to the phase transition of dispersed particles structure are in the hyperbolic relation. (2) It was in ferred that the plastic elements of carbon black group rubber is proportinal to the volume fraction of C phase being formed around particles, and its stress relaxation is due to the structure-stabilizing process by the fracture of plastic elements and the transfer of particles to the stable configuration, on the other hand, the stress relaxation of CaCO3 group rubber without forming C phase is due to the secession process of rubber molecular chains at particle interfaces.
