Elongation of telechelic ionomers under shear: a rheological and rheo-optical study

The behavior under shear of solutions of α,ω-lithium sulfonato polystyrene (α,ω-LiPSS100) in toluene has been investigated by rheo-optics and rheology. Shear-thickening is observed and related to a strong increase of birefringence and a pronounced and rapid alignment of the polymer chains toward the flow direction leading to an important elasticity of the fluids. The draw ratio of the polymer chains under shear has been estimated from the rheo-optical data. When the fraction of loops is taken into account, draw ratios on the order of 4 are calculated in the shear thickening regime