Diversity of Synthetic Approaches to Functionalized Perfluoropolyalkylether Polymers

Abstract

Perfluoropolyalkylethers (PFPAEs) are a class of fluorinated polymers having −OCF2–, −OCF2CF2–, and −OCF2CF­(CF3)– as common chain units. The ether linkages distinguish them from other famous fluorinated polymers such as poly­(tetrafluoro­ethylene). Their higher mobility highlighted by below zero glass transition temperatures permit them to be noncrystalline, which makes them easy to use for many applications. They possess interesting tribological properties, combined with an excellent thermal and chemical stability, make them very useful as lubricants. However, after chemical modifications, they also demonstrated to be very useful in numerous applications as surfactants, electrolytes, high performance coatings, vitrimers, or microfluidic devices, to give a few examples. This Perspective aims to summarize all the chemical modifications reported on these PFPAEs to provide a new insight into their potential utility in emerging fields. Indeed, the end group can modulate the properties of PFPAE-based materials such as lubricity, superhydrophobicity, biofouling, antibacterial activity, amphiphilicity, and the ability to react further with comonomers under photochemical and thermal processes. It can also modulate their intrinsic properties such as viscosity and solubility in common organic solvents. The chemical modifications are sorted in five main parts: the condensation reactions, the nucleophilic reactions, the click chemistry reactions, the radical reactions, and finally reactions going through other mechanisms or requiring a multistep process. They can be employed as such or for further polymerization processes depending on the targeted application. Examples of applications are thoroughly described to demonstrate their current usefulness and to help provide direction for their future use.

An Ultra‐Low‐Temperature Elastomer with Excellent Mechanical Performance and Solvent Resistance

“…[ 12 ] Hence, we suppose that the perfluoropolyether oligomer is currently the only candidate that might be formulated as an extremely low temperature rubber with excellent oil or solvent resistance. Over the past 60 years, since the first application of PFPE, [ 13 ] several pioneering works [ 14–20 ] have been reported on the PFPE‐based low‐temperature elastomers, while most of them were focused on tuning the comprehensive physical and thermal properties and introduced relatively high percentage of nonfluorinated components in the elastomeric network, like crosslinking agents or other hard phases. None of them have ever achieved or reported excellent elasticity below −80 °C.…”

Preparation of Degradable Superhydrophobic Mg/P/Z/F/H Composite Materials and Their Anticorrosion

“…etc) and various metal alloys (Fe, Cu, Ni, Co) containing heavy metal ions. [17][18][19][20][21][22] With the wide application of metals and the undegradable polymer, the environment risks of various heavy metals (especially Pb, Cu, Cd, Cr, and Ni) and the plastic particle pollution is becoming seriously under different corrosive medium. Here the environmentally degradable materials (Magnesium, Polycaprolactone and ZnO) were used to prepare the multifunctional superhydrophobic constructional materials.…”

Cyclic Perfluoropolyether: Distinct Film Formability and Thermostabilization Upon Recyclable Cyclic–Linear Topological Transformation

“…[ 3 ] Among them, perfluoropolyalkylethers (PFPAEs) have been well studied since the 1970s [ 4 ] and have aroused significant growth of interest. [ 5 ] Perfluoropolyether (PFPE) is a PFPAE utilized in a wide range of products owing to its flexible, noncombustible, and chemically robust nature. [ 5,6 ] The immiscibility of PFPEs against nonfluorine‐containing small molecular groups or polymers generally causes microphase separation, as represented by materials combined with either oligo(ethylene oxide) or poly(ethylene oxide).…”

“…[ 5 ] Perfluoropolyether (PFPE) is a PFPAE utilized in a wide range of products owing to its flexible, noncombustible, and chemically robust nature. [ 5,6 ] The immiscibility of PFPEs against nonfluorine‐containing small molecular groups or polymers generally causes microphase separation, as represented by materials combined with either oligo(ethylene oxide) or poly(ethylene oxide). [ 7,8 ] However, modification of materials containing PFPE without causing phase separation has been difficult and remains an imperative challenge to further expand the potential applications of fluoropolymers.…”