Chemical etching technique for the investigation of melt-crystallized isotactic polypropylene spherulite and lamellar morphology by scanning electronmicroscopy

The spherulitic and lamellar morphologies of melt crystallized isotactic po lypropylene (iPP) have been investigated according to various crystallizati on temperatures and times. In this study, an appropriate chemical etching c ondition for the observation of iPP morphology by scanning electron microsc opy (SEM) is determined. The optimum etchant formulation is 3 wt% potassium permanganate with the mixed solvent of sulfuric acid and phosphoric acid. The morphologies after etching reveal the microstructure of iPP clearly, su ch as the characterization of aip spherulites and the different lamellar gr owth patterns.