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

Kód výsledku v 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>

Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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).

Název v anglickém jazyce

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

Popis výsledku anglicky

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).

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

10404 - Polymer science

Projekt

<a href="/cs/project/GA16-05886S" target="_blank" >GA16-05886S: Výzkum vlivu smykové a tahové reologie polymerních tavenin na stabilitu produkce meltblown nanovláken a fólií</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Annual Technical Conference - ANTEC, Conference Proceedings

ISBN

978-1-71380-197-9

ISSN

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e-ISSN

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Počet stran výsledku

4

Strana od-do

1164-1167

Název nakladatele

Society of Plastics Engineers

Místo vydání

Danbury

Místo konání akce

Orlando, Florida

Datum konání akce

7. 5. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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