Solid-state NMR studies of structure and dynamics of erucamide/isotactic poly(propylene) blends

Abstract

Solid-state NMR spin diffusion experiments and two-dimensional (2D) 1H-13C NMR experiments have been used to study the phase structure, mobility and domain sizes of blends of isotactic poly(propylene) (i-PP) and erucamide (ERU), a low molecular weight slip and antiblock additive for i-PP films. The study of the proton line shapes in pure erucamide and i-PP together with their blends reveals the mobility of the two components. The mobility is higher in the blends than in erucamide and i-PP when they are considered separately. In addition, 2D wideline separation (WISE) NMR spectroscopy indicates that erucamide molecules show both low and high mobilities depending on the erucamide content in the blend. By measuring the proton spin diffusion with 1H detection, the microdomain dimensions have been estimated quantitatively. The domain sizes range from approximately 13 nm to 60 nm.