Wall slip of HDPEs: Molecular weight and molecular weight distribution effects

Autor:	Mahmoud Ansari, Paul J. DesLauriers, Yong Woo Inn, Savvas G. Hatzikiriakos, Ashish M. Sukhadia
Rok vydání:	2013
Předmět:	Physics::Fluid Dynamics Materials science Slip velocity Mechanics of Materials Wall slip Mechanical Engineering Dispersity Molar mass distribution Thermodynamics General Materials Science Slip (materials science) Condensed Matter Physics Physics::Geophysics
Zdroj:	Journal of Rheology. 57:927-948
ISSN:	1520-8516 0148-6055
DOI:	10.1122/1.4801758
Popis:	The slip behavior of several high-density polyethylenes (HDPEs) is studied as a function of molecular weight (Mw) and its distribution for broad molecular weight distribution metallocene and Ziegler–Natta catalyst resins. It is found that slip depends strongly on Mw and its distribution. First, the slip velocity increases with decrease of molecular weight, which is expected to decay to zero as the Mw approaches a value with characteristic molecular dimension similar to surface asperities. For HDPEs that exhibit stick–slip transition, the slip velocity has been found to increase with increase of polydispersity. The opposite dependence is shown for HDPEs of wider molecular weight distribution that do not exhibit stick–slip transition. A criterion is also discussed as to the occurrence or not of the stick–slip transition which is found to depend strongly on Mw and its distribution.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7c204920e9b1f3e6a6a0481ea4cdfaac https://doi.org/10.1122/1.4801758 Zobrazit plný text záznamu