Fig. 5: Terminal region of the Maxwellian copolymer poly(S70-r-DIB30).
From: Unraveling the rheology of inverse vulcanized polymers
The drop off in storage modulus, here due to the organopolysulfide exchange reaction, is a feature of polymers containing dynamic covalent bonds in general that show a more rapid stress relaxation as the rate of reaction increases with temperature, thus shortening the rubbery plateau region. This unshifted data also emphasizes the importance of the vertical shift factor as its value increases as the equilibrium constant shifts towards the dissociated thiyl radicals.
