Solution behavior of polyimide‐graft‐polystyrene copolymers in selective solvents

Abstract

A polyimide-graft-polystyrene (PI-g-PS) copolymer with a polyimide backbone and polystyrene side chains was synthesized by the "grafting from" method using styrene polymerization on a polyimide multicenter macroinitiator via ATRP mechanism. The side chain grafting density z 5 0.86 of PI-g-PS is rather high for graft-copolymers synthesized by the ATRP method. Molecular characteristics and solution behavior of PIg-PS were studied in selective solvents using light scattering and viscometry methods. In all solvents, the backbone tends to avoid contact with a poor solvent. To describe the conformation and hydrodynamic properties of PI-g-PS macromolecules in thermodynamically good solvents for side chains and PI-g-PS, the wormlike spherocylinder model is used. Macromolecules of the studied graft-copolymer are characterized by high equilibrium rigidities (Kuhn segment length >20 nm). In Hconditions, PI-g-PS macromolecules may be modeled by a rigid prolate ellipsoid of revolution with a low asymmetry form and a collapsed backbone as the ellipsoid core.

Synthesis, Structure, Hydrodynamics and Thermoresponsiveness of Graft Copolymer with Aromatic Polyester Backbone at Poly(2-isopropyl-2-oxazoline) Side Chains

“…Therefore, the thermodynamic quality of the solvent with respect to the backbone and side chains plays an important role. The solution behavior of amphiphilic graft copolymers has been studied for aromatic polyimides grafted with vinyl polymers such as polystyrene, polymethylmethacrylate, poly-tert-butyl acrylates, their copolymers with polymethacrylic acid [ 21 , 22 , 23 , 24 , 25 ], and enzymatically synthesized polyesters grafted with hydrophilic and hydrophobic side chains [ 26 ]. It is shown that copolymers with a low grafting density tend to form supramolecular structures due to aggregation of the polyimide backbones.…”

Methods of controlled radical polymerization for the synthesis of polymer brushes

“…In selective solvents of various thermo dynamic qualities for the backbone and side chains, such polyimide brushes assume conformations of a more or less elongated ellipsoid of revolution [142,143] or form a nearly spherical core-shell structure with the collapsed backbone (core) surrounded by side chains protruding into the solution [143], as con firmed by the computer simulation method [144].…”

Synthesis of polycaprolactone-polyimide-polycaprolactone triblock copolymers via a 2-step sequential copolymerization and their application as carbon nanotube dispersants

“…Other polyimide-vinyl block copolymers have been synthesized via atom transfer radical polymerization (ATRP), including polyimidegraft-polystyrene and poly(methyl methacrylate)-block-polyimide-block-poly(methyl methacrylate). [5][6][7] Polyimide-polyester block copolymers have hitherto not been directly synthesized. Ring-opening polymerization has not previously been employed in the synthesis of PI-based copolymers.…”