J. Phys. France 51, 2205-2226 (1990)
DOI: 10.1051/jphys:0199000510190220500

Kinetic theory of microphase separation in block copolymers

E.L. Aero, S.A. Vakulenko et A.D. Vilesov

Institute of Macromolecular Compounds, USSR Academy of Sciences, V.O., Bolshoi pr. 31, 199004 Leningrad, U.S.S.R.

Abstract
A semiphenomenological theory that has the advantage of taking into account nonlinear and nonlocal contributions in the free energy for microphase separation of block copolymers is proposed. A kinetic nonlinear equation defining the process of structure formation from a melt is obtained, and its analytical solution at the melt-structure transition temperature is examined. In this region, the structure formation proceeds in two stages. The first one is characterized by damping of all but stable Fourier-components of density distribution and the second, by stabilization of the amplitude of the distribution. Characteristic times of these processes are estimated. The applied approach allows a comparatively simple definition of lamellar, hexagonal and body-centered cubic structures near Ts. Equilibrium structures at T <<; Ts are described as well.

PACS
6141 - Polymers, elastomers, and plastics.
6125H - Macromolecular and polymer solutions; polymer melts; swelling.
6475 - Solubility, segregation, and mixing; phase separation.

Key words
free energy -- polymer structure -- segregation