THE EFFECT OF FLUCTUATION NETWORK IN CROS S-LINKED RUBBER ON THE MIGRATION OF LOW-MOLECULAR-MASS COMPONENT FROM THE SYSTEM COMPRISING A CROSS-LINKED RUBBER AND A LOW-MOLECULAR-MASS HYDROCARBON

Kinetics of the migration of a low-molecular-mass hydrocarbon out of t he bulk of cross-linked natural rubber, butadiene rubber, and butadien e-styrene rubber was studied. With increasing the content of hydrocarb on in the rubbers (to 50%), an increase in the rate of its migration f rom polymer bulk was shown not to correlate with an increase in the le vel of internal stresses, which were induced in the network of chemica l bonds and were responsible for the migration of a low-molecular-mass additive out of the bulk to the surface. The fluctuation network, whi ch is preserved in the rubbers at low degrees of their swelling in mel ts of hydrocarbons, and the network of chemical bonds were in the stre ssed state. As a result the total level of internal stresses induced b y crystallization of hydrocarbons in the bulk of cross-linked rubbers was shown to increase.