Spinodal decomposition with varying chain lengths and its application to designing polymer blends

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 35; no. 6; pp. 897 - 907
• Main Authors: He, David Qiwei, Nauman, E. B.
• Format: Journal Article
• Language: English
• Published: New York John Wiley & Sons, Inc 30.04.1997; Wiley
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; spinodal decomposition; ternary polymer blends; Thermal and thermodynamic properties; variable chain lengths; Binary mixture; Ternary mixture; Phase separation; Spinodal decomposition; Theoretical study; Polymer; Diffusion equation; Modeling; Molecular weight property relation
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/(SICI)1099-0488(19970430)35:6<897::AID-POLB4>3.0.CO;2-F

The diffusion equations of spinodal decompositions with unique diffusivities for each species are derived for binary systems and ternary systems. These dynamic equations are linearized to show that the minimum size for growth is independent of diffusivity and is identical to the thermodynamic minimum on phase volume. Increases in chain length will destabilize mixtures and increase quench depth. Numerical simulations were conducted for two‐dimensional systems. The considerable influences of chain lengths on morphology represent a competition between smaller diffusivities and larger quench depth when chain length is increased. These influences on several important morphologies in binary and ternary systems are described. The understanding of independent variable chain lengths represents one further step towards the systematical design of polymer blends. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 897–907, 1997