Isotactic polypropylene crystallized from the melt. I. Morphological study

✍ Scribed by Ismail A. Al-raheil; Ali M. Qudah; Mohammed Al-share'

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 532 KB
• Volume: 67
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980214)67:7<1259::aid-app15>3.0.co;2-x

✦ Synopsis

The spherulitic structure of isotactic polypropylene (iPP) from the melt was studied by polarized light and scanning electron microscopy. From the crystallization morphology, it can be observed that crystallization of iPP from the melt below 132ЊC forms two types of spherulites, termed aand b-spherulites. The structure of iPP isothermally crystallized above 132ЊC shows a-type only. The a-spherulites have a complex crosshatched array of radial and tangential lamellar structures, while b-spherulites have, to some extent, simpler lamellar morphology with lower crosshatching content compared with a-type. However, in a-spherulites the radial lamellar thickness is greater than that of tangential lamellae, but in b-spherulites the radial and tangential lamellae have approximately the same thickness.