The Morphology and Corresponding Rheological Properties of Phase-Separating Polymer Blends Subject to a Simple Shear Flow

• Published in: Macromolecular theory and simulations Vol. 11; no. 4; pp. 429 - 437
• Main Authors: Luo, Kaifu, Yang, Yuliang
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag GmbH 01.04.2002; WILEY‐VCH Verlag GmbH; Wiley
• Subjects: Applied sciences; Chains; computer simulations; Exact sciences and technology; Mathematical analysis; Morphology; Organic polymers; phase behavior; Physicochemistry of polymers; Properties and characterization; Relaxation time; Rheological properties; rheology; Shear strain; Simulation; Terminals; Thermal and thermodynamic properties; Polymer blends; Structuration; Molten state; Computer simulation; Shear flow; Phase separation; Theoretical study; Ginzburg Landau equation
• ISSN: 1022-1344; 1521-3919
• DOI: 10.1002/1521-3919(20020401)11:4<429::AID-MATS429>3.0.CO;2-F

The chain‐stretching effect on the morphology and the corresponding rheological properties are analyzed theoretically. In order to confirm the theoretical analysis, the simulations based on the time‐dependent Ginzburg‐Landau (TDGL) equation with the free energy functional contains the information of chain conformation have been performed in q‐space by means of the semi‐implicit Fourier spectral method. This method is more efficient and accurate, and moreover, the periodic boundary condition used in r‐space cell dynamics scheme (CDS) can be released. The simulation results agree with the theoretical analysis quite well and show that the chain‐stretching effect decreases with the increase of shear strain. For the critical system with a longer terminal Rouse relaxation time, two peaks are observed in the transient shear viscosity. It is also found that, when the shear strain is small, the chain‐stretching effect on the morphology and the corresponding rheological properties are enhanced when the terminal Rouse relaxation time is longer.