Abstract
1. Raising the temperature of vulcanizates containing carbon black causes changes in the carbon structures, which can be estimated by the value of specific electric resistivity ρ and the index n in the equation: I=cVn, relating the strength of the current I with the voltage V. 2. These changes are nearly independent of the type of rubber and are governed chiefly by the type of carbon black. 3. The change of electric resistivity of vulcanizates with temperature follows an exponential law, and can be expressed by the equation : ρt=ρ0 eαt. 4. The sign of the coefficient α is negative for vulcanizates containing channel carbon black, and positive for those containing nozzle black or lamp black. 5. Heating of vulcanizates (up to 100°) for 30 minutes causes destruction of the nozzle black and lamp black particles, but causes little apparent destruction of channel black structures. 6. Prolonged heating (10 hours or more) at temperatures above 60° C causes destruction of the particles of all the carbon blacks studied. This detruction is more extensive in the case of nozzle and lamp blacks than in the case of channel black. 7. During heat treatment of mixtures containing channel black, it is chiefly the carbon-rubber bonds that are destroyed (the index n decreases); whereas in mixtures containing nozzle, furnace and lamp blacks, it is chiefly the carbon-carbon bonds that are destroyed (the index n increases). 8. The higher the temperature during deformation and relaxation, the greater is the degree of restoration of the carbon structures which are destroyed during deformation. 9. The degree of restoration of the carbon structures under identical conditions of deformation and relaxation of vulcanizates containing nozzle black is greater than that of corresponding vulcanizates containing channel black.
EFFECT OF MECHANOCHEMICAL TREATMENT OF INGREDIENTS ON STRUCTURE AND PROPERTIES OF RUBBER MIXTURES AND RUBBERS ON BASIS ОF 1,4-CIS-POLYISOPRENE