Morphology of crazes in glassy polycarbonate

Abstract
The craze morphology of amorphous polycarbonate in bulk samples and thin films has been examined using electron microscopy techniques. Results indicate polycarbonate crazes induced by heat or solvent have a “lamellar” texture oriented nearly perpendicular to the tensile stress direction. However, the craze texture of polycarbonate blended with antiplasticizer is observed to be fibrillar, similar to polystyrene, whereas the craze texture of polycarbonate blended with plasticizers is observed to contain crystallites. Transmission electron microscopy studies demonstrate that craze initiation does not occur by void formation or cavitation but rather by a local thinning or yielding at the craze tip. The initial stage of craze development appears similar for crazes in both polystyrene and polycarbonate.