Viscoelastic Retardation Time Computations for Homogeneous Block Copolymers.

摘要

The Rouse-Bueche-Zimm molecular theory of viscoelasticity has been extended to compute the retardation time spectra of block copolymers of various configurations and compositions. The basic assumption of the block copolymer model is that the effect of the presence of foreign blocks on the retardation spectrum is due exclusively to the difference in the friction coefficients. Mathematically this modification is accomplished by introducing into the equations of motion a frictional coefficient matrix. Retardation spectra can then be obtained by numerically solving for the eigenvalue spectrum on a computer. Results show that the viscoelastic retardation spectra and maximum retardation times of the block copolymers vary as a function of the block configurations, block composition and the friction coefficient ratio of the blocks.