Understanding and controlling the structure of polypropylene/layered silicate nanocomposites

• Published in: Journal of polymer science. Part B, Polymer physics Polymer physics, 2008-12, Vol.46 (24), p.2683-2695
• Main Authors: Chrissopoulou, K, Altintzi, I, Andrianaki, I, Shemesh, R, Retsos, H, Giannelis, E.P, Anastasiadis, S.H
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; nanocomposites; Polymer industry, paints, wood; polymeric compatibilizer; polypropylene; Technology of polymers
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.21594

The miscibility and structure in polypropylene/layered silicate nanocomposites is systematically investigated utilizing a maleic-anhydride grafted polypropylene with a low degree of functionalization acting as the compatibilizer. The morphology of the hybrids can be modified from phase separated to almost completely exfoliated in a controlled way by varying the ratio α of the compatibilizer to the organophilized clay; this ratio α is found to be the most important parameter in determining the final structure whereas exfoliated structures can be obtained for α values of 9 or higher. Furthermore, utilization of a "masterbatch" procedure can enhance the degree of exfoliation even for smaller values of α; in that case, polypropylene is essentially mixed with the already dispersed "hairy" platelets. Investigation of the thermal stability of the micro- and nanocomposites shows that high degree of exfoliation is vital in increasing the temperature that the polymer starts to degrade.