Computer Chemistry Consultancy - XML4Pharma, Katzelbachweg 18, A-8052 Thal, Austria,

Scientific Publications of Jos Aerts

Structure and Rheology of Aramid Solutions: Transient Rheological and Rheooptical Measurements

S.J.Picken, J.Aerts, H.L.Doppert, A.J.Reuvers and M.G.Northolt

Macromolecules, 24, 1366-1375 (1991)


Some results are presented on the rheology of the lyotropic nematic phase of the aramid polymers poly(p-phenyleneterephthalamide) and poly(4,4'-benzanilidyleneterephthalamide) in concentrated sulfuric acid. Controlled-stress and controlled-strain rheometry, polarization microscopy, conoscopy, and synchrotron X-ray scattering were used to study the change in the structure of the solutions during the start-up of simple shear flow. The experimental results are discussed in terms of a qualitative model for the structure of these solutions. The development of orientation during the start-up of flow is explained by using an affine deformation model.