Abstract
In the case when scissions of both mainchains and crosslinks occur at the same time, the theoretical relationship between the change of chemical structure and the properties of the polymer network chains has already been studied by us. Then calculated and observed stress-relaxation curves of TT-cured natural rubber were compared, and it was found that the curve observed usually falls below the calculated one.
This discrepancy is considered to be based upon the reason of our imperfect network degradation theory, so the corrected theory in which dangling mainchains near by crosslinks suffered scission are ineffective in relation to stress relaxation was proposed and the new theoretical equations (36) and (44) were derived. This new theoretical curve falls below the old theoretical one and approaches to the observed one.
