Novel non-fluorinated surfactants for emulsion polymerization of fluorinated monomers

In order to replace toxic fluorinated surfactants such as PFOA and GenX, herein we report a series of non-fluorinated surfactants (NFS) for the emulsion polymerization of fluorinated monomers. The surfactant is a statistic copolymer synthesized from free radical polymerization of poly(ethylene oxide) methacrylate (PEGMA) as hydrophilic monomer with methyl methacrylate (MMA) or tert-butyl methacrylate (TBMA) as hydrophobic comonomer. With properly designed hydrophile lipophile balance (HLB), monomer ratio, and the length of PEG segments, the polymeric NFS form unimolecular micelles in water, which facilitates the emulsion polymerization of fluorinated monomers including vinyl difluoride (VDF) where the solid content of emulsion can be higher than 25 wt% without the occurrence of significant coagulation. The optimized loading ratio of NFS is as low as 88 ppm which is ten times lower than that of fluorinated surfactants. The results demonstrate that the statistic copolymers construct unimolecular micelles to be powerful NFS for the emulsion polymerization of fluorinated monomers. [Display omitted] Per- and polyfluoroalkyl substances (PFAS) surfactants have garnered significant attention due to their enduring presence in the environment, propensity for bioaccumulation, and inherent toxicity. In the past, PFAS surfactants found extensive application in the realm of fluoropolymer synthesis, owing to their exceptional interfacial characteristics and chemical stability. However, recent efforts by major global fluoropolymer producers such as Arkema, 3 M, Daikin, and Kureha have focused on developing non-fluorinated surfactants (NFS) based on polyethylene oxide (PEO) segment. Despite these advancements, current commercially available NFS options still exhibit shortcomings in terms of adequate interface absorption and chemical inertness. In this contribution, we introduce a rationally designed methacrylate copolymers as NFS for the polymerization of fluorinated vinyl monomers, strategically engineered to mitigate undesirable chain transfer reactions and bolster interface absorption. Additionally, experimental results corroborate the design rationale behind the formation of unimolecular micelles by methacrylate copolymer NFS. Several crucial points merit considerations in light of these findings.•We have conducted a systematic study to explore the correlation between the structural parameters of designed NFS and their performance in emulsion polymerization. The experi