Positron Lifetimes in Blends of Recycled Polystyrene and Polyethylene

Positron lifetimes and intensities are used to characterize the microstructure of products made from the blending of recycled plastics: post‐industrial polystyrene and post‐consumer high density polyethylene. For samples of various compositions, the extent of polymeric microheterogeneity (homogeneity) is estimated, the degree of crystallinity of the polyethylene phase, and, using a trapping model, the size and number of microvoids. The results obtained correlate well with wide‐angle x‐ray diffraction measurements and mechanical properties. A unique morphology which results in optimal properties is identified using positron annihilation.