TY - JOUR

T1 - SUPERPOSITION OF SMALL DEFORMATIONS ON LARGE DEFORMATIONS

T2 - MEASUREMENTS OF THE INCREMENTAL RELAXATION MODULUS FOR A POLYISOBUTYLENE SOLUTION.

AU - McKenna, G. B.

AU - Zapas, L. J.

PY - 1985

Y1 - 1985

N2 - The incremental relaxation modulus DELTA G(t) for a concentrated solution of polyisobutylene has been determined from step-shear experiments in which a small deformation DELTA gamma was superimposed on a large deformation gamma //1; DELTA G(t) was found to decrease with increasing gamma //1 and to increase with the time t//e after the imposition of the large deformation. It was also observed that the 'apparent relaxation spectrum' associated with DELTA G(t) narrows and shifts to shorter times when compared to the spectrum associated with the linear viscoelastic relaxation modulus G(t). The results are well described by the nonlinear constitutive equation of the BKZ elastic fluid theory.

AB - The incremental relaxation modulus DELTA G(t) for a concentrated solution of polyisobutylene has been determined from step-shear experiments in which a small deformation DELTA gamma was superimposed on a large deformation gamma //1; DELTA G(t) was found to decrease with increasing gamma //1 and to increase with the time t//e after the imposition of the large deformation. It was also observed that the 'apparent relaxation spectrum' associated with DELTA G(t) narrows and shifts to shorter times when compared to the spectrum associated with the linear viscoelastic relaxation modulus G(t). The results are well described by the nonlinear constitutive equation of the BKZ elastic fluid theory.

UR - http://www.scopus.com/inward/record.url?scp=0042021659&partnerID=8YFLogxK

U2 - 10.1002/pol.1985.180230816

DO - 10.1002/pol.1985.180230816

M3 - Article

AN - SCOPUS:0042021659

VL - 23

SP - 1647

EP - 1656

JO - Journal of polymer science. Part A-2, Polymer physics

JF - Journal of polymer science. Part A-2, Polymer physics

SN - 0449-2978

IS - 8

ER -