“…They originated from hindered amines used as stabilizers. Lucarini et al carried out detailed studies on PP using 1D EPRI [23][24][25], Marek et al extended the work to polystyrene [26], while Schlick and collaborators used both 1D EPRI and 2D SSI to study the degradation of heterophasic system such as poly(acrylonitrile-butadiene-styrene) and propylene-ethylene copolymers [27,28], or very recently to measure diffusion coefficients of nitroxide radicals in propylene-ethylene copolymers [29] (for review on this topic see Refs. [30][31][32] by Schlick).…”