Rigid Fluorinated Polyimides with Well-Defined Polystyrene/Poly(pentafluorostyrene) Side Chains from Atom Transfer Radical Polymerization

Abstract

Comb-shaped copolymers consisting of rigid fluorinated polyimide (FPI) backbone and well-defined polystyrene (PS) side chains (FPI-cb-PS), or poly(pentafluorostyrene) (PFS) side chains (FPI-cb-PFS), were synthesized by atom transfer radical polymerization (ATRP) from the bromide-containing FPI macroinitiators (FPI-Br). The sizes of the FPI-Br macroinitiators (consisting of 14 repeat units in the rigid backbone) and cleaved PS and PFS brushes (consisting of 35−144 and 32−93 repeat units, respectively) were estimated from the gel permeation chromatography (GPC) results. The lengths of the PS and PFS side chains determined from 1H NMR spectroscopy were comparable to those determined from GPC or theoretical analysis. X-ray photoelectron spectroscopy (XPS) results confirmed the presence of grafted PS and PFS side chains on the respective FPI-cb-PS and FPI-cb-PFS copolymers as well as the presence of one ATRP bromide initiator per FPI repeat unit in the FPI-Br macroinitiator. Orderly arrays of the comb-shaped m...