Figure 1

The startup of nominal extension viscosities ${\overline{\eta }}_N^{+}$ as function of the time $t$. $t$ is the time from the start of the extension (at $t=0$). The bullets (●) are measurements from Fig. 7 in 11. The set extensional rates ${\dot{ϵ}}_N$ are 24, 16, 11, 8, 6.4, 4.8, 3.2, 1.6, 0.8, and $0.4{\mathrm{s}}^{-1}$ from the left to the right curve. The solid lines are the corresponding theoretical prediction from Eqs. (1, 2), with the use of the parameters in Table  for the 100 K SBR melt. The dashed line is the linear viscoelastic envelope.Reuse & Permissions

Figure 2

The solid lines are the dynamic development of the boundary contours in the finite element modeling (of a 100 K SBR melt). $L_0/R=12.7$. The dashed lines are symmetry lines. The startup of flow, until a set strain of ${ϵ}_{N,0}$ (here ${ϵ}_{N,0}=1.4$) using a set extension rate of ${\dot{ϵ}}_N$ (here ${\dot{ϵ}}_N=9.6{\mathrm{s}}^{-1}$), is shown. It is following by the dynamic development of the boundaries, where the distance between the left and right boundaries is fixed. An initial perturbation of the cylindrical sample of $H/R=0.015$ and a width of $W/R=0.2$ is used in these finite element computations.Reuse & Permissions

Figure 3

The engineering stress $F/A_0$ as a function of the time from the initiation of the extension ($t=0$) for the 100 K SBR melt. The initial imposed set strain ${ϵ}_{N,0}$ is 1.8 (△), 1.6 (◇), 1.4 (○), and 1.2 ($+$), where the nominal extension rate ${\dot{ϵ}}_N=9.6{\mathrm{s}}^{-1}$. The measurements are from Fig. 6 in 11. The solid lines are the corresponding finite element computations to the symbols. They are based on Eqs. (1, 2) (using the Currie approximation), with the parameters in Table  for the 100 K SBR melt. A fixed initial perturbation of the cylindrical sample height of $H/R=0.015$ and a width of $W/R=0.2$ is used in the finite element computations.Reuse & Permissions

Figure 4

The engineering stress $F/A_0$ as a function of the time from the initiation of the extension ($t=0$). The 170 (◇), 250 (○), and 500 K ($+$) SBR melts are represented in the left to the right curves, respectively. The initial imposed set strain rates ${\dot{ϵ}}_N$ are 4.8 (◇), 2.6 (○), and $0.8{\mathrm{s}}^{-1}$ ($+$) for the 170 (◇), 250 (○), and 500 K ($+$) SBR melts, respectively. The initial imposed set strain ${ϵ}_{N,0}=1.1$. The solid lines are the corresponding finite element computations to the symbols. They are based on Eqs. (1, 2) (using the Currie approximation), with the parameters in Table  for the respective SBR melts. A fixed initial perturbation of the cylindrical sample height of $H/R=0.05$ and a width of $W/R=0.2$ is used in the finite element computations.Reuse & Permissions

Figure 5

Time to break $t_c$ relative to the Rouse time ${\tau }_R$ (from Table ) as function of the set strain where the rotation is halted ${ϵ}_{N,0}$. The measurements are from Fig. 5 in 10 and Fig. 6 in 11. The initial imposed set strain rates ${\dot{ϵ}}_N$ are 9.6 (△), 4.8 (◇), 2.6 (○), and $0.8{\mathrm{s}}^{-1}$ ($+$) for the 100 (△), 170 (◇), 250 (○), and 500 K ($+$) SBR melts, respectively. The lines are the finite element computations, based on Eqs. (1, 2) (using the Currie approximation), with the parameters in Table  for the respective SBR melts. The dashed lines are finite element computations for the 100 K SBR melt and the solid lines for the 250 K SBR melt. A fixed initial perturbation of the cylindrical sample height of $H/R=0.05$ and a width of $W/R=0.2$ is used in the computations for the two lines to the left, where $H/R=0.015$ (the width is unchanged $W/R=0.2$) for the two lines to the right.Reuse & Permissions