The Behavior of Amphiphilic Molecular Brushes with Polyimide Backbone and Poly(methyl methacrylate) and Polystyrene Side Chains in the Vicinity of Θ Point

The behavior of amphiphilic molecular brushes in the vicinity of the Θ point has been studied by the methods of molecular hydrodynamics and optics upon variation of temperature. As objects of investigation, graft copolymers with polyimide main chain and poly(methyl methacrylate) and polystyrene side chains were chosen. The samples studied differed in the backbone and side chain lengths at a similar degree of grafting. The molecular mass of the samples under investigation was varied in a sevenfold range. For comparison, linear poly(methyl methacrylate) and polystyrene have been studied. It has been shown that the behavior of molecular brushes and linear polymers in the vicinity of the Θ point differs significantly. A more rapid gain in intrinsic viscosity of the solutions of graft copolymers in the vicinity of the Θ point is explained by the simultaneous increase in the volume of macromolecules and in their shape asymmetry.