Polydispersity influence in rheological behavior of linear chains by molecular dynamics

被引：8

作者：

Blanco-Diaz, E. G. ^{[1
]}

Castrejon-Gonzalez, E. O. ^{[1
]}

Rico-Ramirez, V ^{[1
]}

Aztatzi-Pluma, D. ^{[1
]}

Diaz-Ovalle, C. O. ^{[2
]}

机构：

[1] Tecnol Nacl Mexico Celaya, Dept Ingn Quim, Celaya Gto 38010, Mexico

[2] Tecnol Nacl Mexico Roque, Dept Ingn, Celaya Gto 38110, Mexico

来源：

JOURNAL OF MOLECULAR LIQUIDS | 2018年 / 268卷

关键词：

Linear chains; Molecular dynamics; Rheological behavior; Polydispersity; WEIGHT DISTRIBUTION; MELT VISCOSITY; SIMULATION; MODEL; SHEAR; POLYMERS; VISCOELASTICITY; BENZENE; SLIP;

D O I：

10.1016/j.molliq.2018.07.099

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Non-equilibrium molecular dynamics simulations were performed to study the effect of the polydispersity index (PDI) on the rheological behavior of linear chains. Four distributions were studied, in which the number average molecular weight was kept constant and the weight average molecular weight was varied. The rheological behavior was obtained by using the SLLOD equation of motion at 450 K. All flow curves show three regions: a first Newtonian plateau, a shear-thinning, and a second Newtonian plateau. The weight average molecular weight exhibited a strong influence in the shear-thinning behavior. Also, at higher shear-rates, some larger chains suffer instabilities in their conformation, causing the presence of the second Newtonian plateau at the lowest apparent viscosity, which is an indicative that potential flow-induced entanglements may occur. (C) 2018 Elsevier B.V. All rights reserved.

引用

页码：832 / 839

页数：8

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