The existence or not of miscibility of PCP and NR was investigated by dilute solution viscometry (DSV) in an
Ubbelohde capillary viscometer and scanning electronic microscopy (SEM) techniques. The blends of these polymers
were investigated by analysis of viscosimetric parameters: Δb, α, ΔK, μ, β and correlation between the reduced
viscosity mass ratios of blend composition. According to the algebraic signal of the studied parameters,
it was found that there is immiscibility between PCP and NR for all tested mass ratios in this study. The sigmoid
adjusting obtained when the reduced viscosity was plotted versus blend composition indicated immiscibility between
PCP and NR polymers. The film morphology of blends observed by SEMshowed two separated phases indicating
immiscible blend.