This fact implies a higher compatibility
for SBR/toluene system than NR/toluene solution.
However, the dissolution process creates a greater drop in the NR viscosity as it observed in Fig. 2.
It seems to indicate that dissolution process produces a higher vari- ation in the entanglement structure of NR as compared to the SBR [38] because the reduction of the impurities and some of the non-rubber components which act as natural branching points in NR.