Extensional viscosity of associative polymers and their mixtures with spherical polymer micelles

Associative polymers were prepared by modifying the olefin copolymer (OCP) backbone with a small mole fraction of polar groups (stickers). Self-assembled ~30-nm spherical polymer micelles (SPM) contained polymethyl methacrylate (PMMA) core stabilized with poly(lauryl)methacrylate corona.? Extensional viscosity of dilute solutions of associative oil-soluble polymers was investigated using Capillary Breakup Extensional Rheometer (CaBER).?Using the analysis of elasto capillary (EC) thinning, we show that the molecular extensibility of associative polymers decreases as compared for the non-associative OCP with the same molecular weight. However, in the presence of SPM, the extensional viscosity and relaxation time for dilute polymer solutions increase quite significantly.? Possible mechanisms of this effect are discussed in terms of finite extensibility non-linear elastic (FENE) dumbbell model.