Conversion of oscillatory shear data from highly filled polymers by direct numerical integration

Abstract

A procedure was developed to enable the direct numerical integration of the Fourier integral transform equation relating G(t) to G′(ω) by considering integration limits that vary as a function of time and which define a range of discrete sub-intervals within the complete frequency domain data set. The method provides results that are in very close agreement to results determined from a relaxation spectrum. However, at low values of time the solution to the variable limit integral transform is sensitive to the absence of a contribution beyond the upper experimental limit of the frequency domain data.