Mechanical Creep and Recovery of Poly(styrene-b-ethylene/butylene-b-styrene)(SEBS), Sulfonated SEBS (sSEBS), and sSEBS/siticate Nanostructured Materials

Creep and recovery of poly(styrene-b-ethylene/butylene-b-styrene) (SEBS) and sulfonated SEBS (sSEBS) materials having various percent sulfortation, some of which were exchanged with monovalent counterions, and sSEBS/silicate hybrids, were investigated. Explanations offered for tensile and shear creep reduction for low degrees of sulfortation involved hydrogen bonding between SO3H groups and/or observed frustrated morphologies. At higher sulfonation levels, an increase in overall percent strain was rationalized in terms of either a more distinct EB phase morphology, or to residual water bound to sulfonic acid groups. This effect was also observed when the acid form materials were ion-exchanged with monovalent counterions. The behavior of silicate-containing systems is situational and less understood. An equation for a modified Burgers viscoelastic model was seen to fit the creep data very well. Copyright (c) 2005 John Wiley C Sons, Ltd