Effect of molecular weight on dynamics of linear isotactic polypropylene melt at very high shear rates

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F18%3A63520671" target="_blank" >RIV/70883521:28110/18:63520671 - isvavai.cz</a>
Result on the web
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DOI - Digital Object Identifier
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Result language
angličtina
Original language name
Effect of molecular weight on dynamics of linear isotactic polypropylene melt at very high shear rates
Original language description
In this work, three isotactic linear polypropylenes, with weight average molecular weights between 56 250 - 75 850 g/mol, have been characterized at 230 o C over a very wide shear rate range. A low shear rate primary Newtonian plateau, a pseudoplastic region and a well developed secondary Newtonian plateau were identified for all the polypropylene melts. Flow activation energy at low (E0) and high (E) shear rates was found to be 56.590 kJ/mol and 25.204 kJ/mol, respectively. For the first time, it has been discovered that the secondary Newtonian viscosity, , depends linearly on the weight average molecular weight, Mw, in log-log scale as 1.084 w 6 1.19 10 M     . The observed slope close to 1 between  and Mw suggests that polymer chains in the melt are disentangled at the secondary Newtonian plateau region. This conclusion is supported by the experimental observation that the high shear rate flow activation energy E for given PP melts is comparable with the flow activation energy of PP like oligomer (squalane, C30H62; 2,6,10,15,19,23- examethyltetracosane).
Czech name
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Czech description
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Project
<a href="/en/project/GA16-05886S" target="_blank" >GA16-05886S: Investigation the effect of polymer melt shear and elongational rheology on production stability of meltblown nanofibers and films</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2018
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection
Annual Technical Conference - ANTEC, Conference Proceedings
ISBN
978-1-71380-197-9
ISSN
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e-ISSN
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Number of pages
4
Pages from-to
1164-1167
Publisher name
Society of Plastics Engineers
Place of publication
Danbury
Event location
Orlando, Florida
Event date
May 7, 2018
Type of event by nationality
WRD - Celosvětová akce
UT code for WoS article
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