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Blends of polymer solutions of poly(N-isopropylacrylamide-co-dopamine methacrylamide) (NIDO) and poly(N-isopropylacrylamide-co-4-vinylphenylboronic acid) (NIBA) in aqueous solutions were studied rheologically at pH ≈ 9. The functional catechol group of NIDO and the boronic acid group of NIBA could form coordinative complexes, which are strong, yet could be broken by high deformation, while they could reconfigure quickly within 1 min on a macroscopic scale. The linear and nonlinear behaviors of these materials vary significantly for different component mixing ratios. At a total polymer concentration of 10 w/v %, the 1:1 mixture (wNIBA/wNIDO) of the two polymers yields the strongest gel compared with asymmetric blends. The nonlinearity intensities (In/I1) of the materials increase proportionately with strain γ0, but once a significant nonlinearity is reached, they show lower nonlinearity intensities, which is unlike regular nonassociative single phase polymer melts and solutions. Interaction of polymer NIDO and NIBA and the formed supramolecular gels' properties will be clarified by large amplitude oscillatory shear characterization.Blends of polymer solutions of poly(N-isopropylacrylamide-co-dopamine methacrylamide) (NIDO) and poly(N-isopropylacrylamide-co-4-vinylphenylboronic acid) (NIBA) in aqueous solutions were studied rheologically at pH ≈ 9. The functional catechol group of NIDO and the boronic acid group of NIBA could form coordinative complexes, which are strong, yet could be broken by high deformation, while they could reconfigure quickly within 1 min on a macroscopic scale. The linear and nonlinear behaviors of these materials vary significantly for different component mixing ratios. At a total polymer concentration of 10 w/v %, the 1:1 mixture (wNIBA/wNIDO) of the two polymers yields the strongest gel compared with asymmetric blends. The nonlinearity intensities (In/I1) of the materials increase proportionately with strain γ0, but once a significant nonlinearity is reached, they show lower nonlinearity intensities, which is unlike regular nonassociative single phase polymer melts and solutions. Interaction of polymer NIDO...

Two series of different isotactic poly(N-isopropylacrylamide) of number average molar masses (Mn) ∼ 100 000, 200 000 and narrow molar mass distribution are prepared by reversible addition fragmentation chain transfer polymerization. Their thermoreversible, physical gels are prepared in benzyl alcohol and rheologically characterized to assess the effect of tacticity and molar masses on the rheological properties. In general, higher tacticity, higher molar mass, and higher concentration lead to stiffer gels and a sol-gel transition at a higher temperature. The results are interpreted based on partial phase separation leading to stiff but labile spongelike structures. The tacticity influences the strength of the phase separation tendency. Concentration and molar mass determine how far reaching and how connected these domains are.