BLENDING EFFECTS ON RHEOLOGICAL PROPERTIES OF MULTICOMPONENT SYSTEMS
(PART V) APPLICATION OF THE BLENDING LAW TO THE ISOCHRONAL STRESS DATA ON FILLER LOADED VULCANIZED RUBBERS
1968 Volume 41 Issue 9 Pages 753-762
Details
1968 Volume 41 Issue 9 Pages 753-762
Being based on the results obtained in this series of study and others, a modified form of Mooney-Rivlin Equation is proposed to describe the tensile stress-strain data on filler-loaded vulcanized rubbers.
S/ [α2- (1/α)] =2C1+ (2C2/α), α=1+ (γ/a), (1)
a= [1-(νe/0.74)].2.5 (2)
(2) HereS and γ are respectively the true stress and the strain for the whole system. C1andC2 are the parameters which characterize the elastic properties of the vulcanized rubber matrix. νe stands for the effective volume fraction of fillers in the system. For small deformations, Eq. (1) can be rewritten in the form,
(S/γ) =6 (C1+C2) /a- (C2/a2) γ (3)
Seven filler-loaded vulcanized samples were prepared for the experiment, and both active and inactive fillers were used. Tensile stress-relaxation measurements were carried out on these samples at a fixed temperature of 35.0°C. The strain ranged from 0.01 to 2.0 for each sample.
Isochronal stress data were then obtained for all runs at a fixed time of twenty minutes to test the validityof those equations. Thus, eqs. (1) - (3) appear to have general applicability for those systems and νewas foundto be nearly identical with the real volume fraction irrespective of the activity of fillers. Although the sum of C1 and C2 increased with the addition of active fillers, it was found that the value of C1 progressively decreased with increasing amount of fillers.
