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dc.title Pergamon-Elsevier Science Ltd cs
dc.title Experimental investigation of flow induced molecular weight fractionation phenomenon for two linear HDPE polymer melts having same Mn and Mw but different Mz and Mz+1 average molecular weights en
dc.contributor.author Musil, Jan
dc.contributor.author Zatloukal, Martin
dc.relation.ispartof Chemical Engineering Science
dc.identifier.issn 0009-2509 Scopus Sources, Sherpa/RoMEO, JCR
dc.date.issued 2012
utb.relation.volume 81
utb.relation.issue 22 October 2012
dc.citation.spage 146
dc.citation.epage 156
dc.type article
dc.language.iso en
dc.identifier.doi 10.1016/j.ces.2012.06.049
dc.subject Die drool phenomenon en
dc.subject Extrusion en
dc.subject Flow induced molecular weight fractionation en
dc.subject Polymer processing en
dc.subject Rheology en
dc.subject Viscoelasticity en
dc.description.abstract In this work, flow induced molecular weight fractionation for two linear HDPE polymers having the same polydispersity index (M ; w/M ; n) but different M ; z and M ; z+1 molecular weight averages, has been experimentally investigated. It has been revealed that first, onset as well as intensity of slip-stick instability and flow induced molecular weight fractionation are in direct relationship, i.e., low molecular weight polymer chains start to fractionate from the main polymer melt stream at the onset of slip-stick flow regime initiating formation of low viscosity layer at the die wall, which leads to its consequent unwanted accumulation at the die lips-die drool phenomenon. Second, due to enhanced melt elasticity (by the presence of long linear chains of linear HDPE polymer), the flow induced molecular weight fractionation is more effective which results in narrow molecular weight distribution of die drool sample containing small amount of long chains. Third, buildup ratio sensitivity to apparent shear rate is the highest in the slip-stick regime and its value increases with increased content of very long chains. Finally, the flow induced molecular weight fractionation takes place only in a very thin layer near the die wall (i.e., within less than 8% of the channel radius for the studied processing conditions and HDPE polymer samples). en
utb.faculty Faculty of Technology
utb.faculty University Institute
dc.identifier.uri http://hdl.handle.net/10563/1002924
utb.identifier.rivid RIV/70883521:28110/12:43867966!RIV13-MSM-28110___
utb.identifier.rivid RIV/70883521:28610/12:43867966!RIV13-MSM-28610___
utb.identifier.obdid 43868057
utb.identifier.scopus 2-s2.0-84864409690
utb.identifier.wok 000307885000014
utb.identifier.coden CESCA
utb.source j-scopus
dc.date.accessioned 2012-09-10T12:21:30Z
dc.date.available 2012-09-10T12:21:30Z
utb.ou Centre of Polymer Systems
utb.contributor.internalauthor Musil, Jan
utb.contributor.internalauthor Zatloukal, Martin
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