The Influence of nucleating agents and process parameters on phase structure of isotactic polypropylene and its copolymer with 3% ethylene

Abstract

The homopolymer of the isotactic polypropylene (iPP) and the random copolymer of the isotactic polypropyleneand 3% ethylene (iPPE) were used in this study. Isotactic polypropylene can be prepared in α, β and γ morphologicalphases depending on its crystallization conditions. The phase β content has a strong influence on mechanical,optical and thermal properties. The samples with nucleating agents (NA) α and β were used. Various processparameters were used to prepare melted samples: two thicknesses and three different cooling regimes. Wide-angleX-ray scattering (WAXD) and scanning electron microscopy (SEM) were used to investigate the phase structure.The results show that iPP without nucleation agents (4mm, <1°C /min) has the highest crystallinity (83.7%). Thesample of iPP with β-NA (4mm, <1°C /min) has the highest phase β (61.3%); the slower cooling regime and thehigher thickness increased the crystallinity (73.3%). iPPE with β-NA (0.4mm, 15°C /min) has the lower amount ofthe phase β (33.8%); the higher thickness and slower cooling regime decreased the amount of the phase β (7.1%)however the crystalline content of iPPE (63.7%) is increased. © 2016 Published by Manufacturing Technology.