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 welldefined 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 1 H 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 macromolecules, consisting of rigid FPI rods (backbones) of 20-30 nm in length and flexible PS brushes (side chains) of 4-6 nm in width, were imaged by atomic force microscopy (AFM). In addition to having a dielectric constant (κ) as low as 2.1, the resulting comb-shaped FPI-cb-PFS copolymer also exhibited good solution processability and good thermal stability (up to 470 °C).

Highly Effective Antiadhesive Coatings from pH‐Modified Water‐Dispersed Perfluorinated Acrylic Copolymers: The Case of Vulcanizing Rubber

“…Perfluorinated acrylic copolymers are particularly interesting materials since they show unique surface properties, such as exceedingly low surface energy, low friction coefficients, repellency to both oil and water, and especially polymers having C‐6 chemistry have been approved for industrial use because of their environmental friendliness . These copolymers are generally utilized in textile or construction industry to obtain hydrophobic and oleophobic surfaces …”

Methods of controlled radical polymerization for the synthesis of polymer brushes

“…A new direction in backbone design that has been under development in recent years is the search for synthetic approaches to molecular brushes based on widely used hi tech thermally stable polycondensa tion type polymers, such as aromatic polysulfones, poly(phenylene oxide), and aromatic polyimides [133][134][135][136][137][138][139]. Different thermodynamic properties of arylene containing polycondensation type main chains and carbon chain side chains in these polymer brushes are responsible for their clearly pronounced diphilic character.…”

“…Another example is the analogous grafting of poly[(meth)acrylates] and polystyrene side chains onto multicenter macroinitiators based on aromatic polyimides [135][136][137][138][139][140].…”

Considerations of functional fluoropolymer structure in the design of acrylic–fluorine hybrid PSAs: Graft versus telechelic cooligomers

“…However, ordinary PSAs exhibit poor wettability on inert materials and bad shear strength at high temperature. Fluoropolymers display various fascinating properties, including chemical, aging and weather resistance, excellent inertness to solvents, hydrocarbons and acids as well as low dielectric constants, flammability and moisture absorption . These specialty materials are high value‐added and gain an irreplaceable position in many challenging applications.…”