An improved permanganic etchant for polyolefines

The technique of permanganic etching reveals lamellar detail in polyethylene and other polyolefines allowing representative melt-crystallized morphologies to be studied with the electron microscope. When etching with the original recipe is prolonged artefacts on a scale of ∼ 10 μm can develop and have probably been misinterpreted as genuine features in some instances. It is emphasized that the conditions of etching should be adjusted to suit the needs of individual specimens. The morphology of artefacts is demonstrated so that they may be recognized as such should they occur. A simple modification of the etchant by incorporating orthophosphoric acid has been found which avoids formation of artefacts on polyethylene.