Capillary Rheometry of Polypropylene: Influence of Molecular Weight on die Swelling
Although there is a relatively large number of papers in the literature concerning the phenomenon of “die swell”, the knowledge of the molecular parameters that influence the expansion of a polymer at the die exit is still scarce, and most of the data collected up to now relate to polystyrene and polyethylene (1–7). To the best of the authors’ knowledge, only Coen and Petraglia (8), Han and coworkers (9), and Fujiyama and Awaya (10) have investigated polypropylene. This polymer is essentially linear and it is well suited for investigations in which a better understanding of the relationship between average molecular weight and rheological properties is required.
KeywordsShear Stress Average Molecular Weight High Density Polyethylene Master Curve Extrusion Temperature
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- 1).C.D. Han, Rheology in Polymer Processing, Academic Press, N.Y, (1976).Google Scholar
- 12).F. Danusso, G. Moraglio, W. Ghiglia, L. Motta and G. Talamini, La Chimica e l’Industria, 41(8), 748 (1950).Google Scholar
- 13).R.I. Tanner, J. Polym. Sci., A-2, 8, 2067 (1970).Google Scholar
- 14).D. Romanini, A. Savadori and G. Gianotti, Rheology of branched LDPE, Polymer, in press.Google Scholar