Rheological behaviour of polypropylene blends utilized in foaming process

0361355 - ÚH 2012 RIV GR eng C - Konferenční příspěvek (zahraniční konf.)
Piyamanocha, P. - Sedláček, T. - Polášková, M. - Filip, Petr - Sáha, P.
Rheological behaviour of polypropylene blends utilized in foaming process.
Latest Trends on Engineering Mechanics, Structures, Engineering Geology. Athens: WSEAS, 2010 - (Martin, O.; Zheng, X.), s. 275-278. Mathematics and Computers in Science Engineering. ISBN 978-960-474-203-5. ISSN 1792-4294.
[WSEAS International Conference on Engineering Mechanics, Structures, Engineering Geology /3./ (EMESEG '10), International Conference on Geography and Geology 2010 (WORLDGEO '10). Corfu (GR), 22.07.2010-24.07.2010]
Grant ostatní: GA MPO(CZ) 2A-1TP1/126
Výzkumný záměr: CEZ:AV0Z20600510
Klíčová slova: polypropylene foam * rheology * strain hardening * foam morphology * pressure dependent viscosity
Kód oboru RIV: BK - Mechanika tekutin

Morphological structure of PP foams represented by the size of the bubbles and bubbles density is affected by rheological properties of the source materials. Various blends of high molecular weight and high melt strength PP were prepared in a twin screw extruder, and foamed. Their shear flow behavior as well as strain hardening during elongation were found to be the factors of a key importance in foaming process optimization. Pressure dependent shear flow behavior of the tested materials was determined using capillary rheometer modified with backpressure chamber, and obtained dependencies of shear viscosity on pressure conditions were analyzed in order to further tailor blend compositions regarding their following use in foaming processes. It has been demonstrated that foam morphology might be controlled not only through degree of bubble coalescence and nucleation rate by the help of optimizing of material components ratio, but also via setting the proper processing conditions.
Trvalý link: http://hdl.handle.net/11104/0198684