The effect of nanoclays on the nucleation, crystallization, and melting mechanisms of isotactic polypropylene

• Published in: Polymer engineering and science Vol. 47; no. 11; pp. 1889 - 1897
• Main Authors: Medellín-Rodríguez, F.J., Mata-Padilla, J.M., Hsiao, B.S., Waldo-Mendoza, M.A., Ramírez-Vargas, E., Sánchez-Valdes, S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.11.2007; Wiley Subscription Services; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Applied sciences; Clay; Composites; Crystallization; Evaluation; Exact sciences and technology; Extrusion; Forms of application and semi-finished materials; Influence; Mechanical properties; Melting points; Nanostructured materials; Nanotechnology; Nucleation; Polymer industry, paints, wood; Polypropylene; Properties; Technology of polymers; Vinyl polymers; Mexico; Clay; Organic clay; Melting; Nucleation; Montmorillonite; Propylene polymer; Dispersion reinforced material; Experimental study; Composite material; Polymer filler interaction; Melt crystallization; Beta form; Isotactic polymer; Concentration effect; Olefin polymer; Nanocomposite; Kinetics; Crystal morphology; Isothermal crystallization
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.20902

The influence of organomodified nanoclay (montmorillonite) on the crystallization and melting mechanisms of isotactic polypropylene (iPP) was studied. Films of both neat polymer and clay nanocomposites were prepared after molecular weight optimization through melt extrusion. Products exhibited the tactoidlike morphology since no compatibilizers were used. The effect of introduction of nanoclay within the polymer was studied through isothermal crystallization and linear heating. The results indicated that low nanoclay concentrations induce the formation of the β‐crystalline structure, its formation being inhibited with high nanoclay contents. Dynamic nonisothermal bulk crystallization experiments indicated that nanoclays act as nucleating agents of iPP. Isothermal, bulk crystallization studies indicated that the crystallization process (induction time and crystallization kinetics) is proportionally accelerated by the nanoclay presence. There was also an accelerated formation of secondary crystallization when nanoclays were present in high concentrations. POLYM. ENG. SCI., 47:1889–1897, 2007. © 2007 Society of Plastics Engineers