Microstructure of Polymers by Tritium Autoradiography

Abstract

Polystyrene, polypropylene, and polyethylene, containing tritiumlabeled additives and crystallized in thin films, were examined with autoradiographic stripping film. In the structures formed by isotactic polystyrene, tritiated atactic polymer concentrated in specific patterns in the outer regions. Polypropylene spherulites showed marked differences in the distribution of the tritiated additive, dilauryl thiodipropionate, whenever their optical properties also differed. Autoradiographs of polyethylene spherulites containing low molecular weight tritiated polyethylene exhibited concentric ring patterns similar to those observed on viewing the polymer film in a polarizing microscope.