Gujarat Fluorochemicals: A hidden fluorine story

Article: https://cen.acs.org/materials/polymers/fluoropolymer-makers-trying-hold-business/101/i8

Interesting view points:

1. European Chemicals Agency published a proposal from five member countries to ban per- and polyfluoroalkyl substances (PFAS) containing at least one fully fluorinated carbon atom—an estimated 10,000 molecules in all, including popular fluoropolymers. Member states would vote on a ban in 2025; if it’s enacted, exceptions for fluorinated chemicals that cannot be replaced with alternative chemistries would expire in 7–12 years.

2. You’re talking about replacing a chemistry that’s been around for 60, 70, 80 years.

3. The European proposal, if it stands unchanged, would spell the eventual end for common fluoropolymers like PTFE and PVDF.

4. Arkema:

• • Arkema, another fluoropolymer maker, said that fluoropolymers made without fluorosurfactants ought to be exempted from the proposed European regulations.
• • uses no fluorosurfactants in the US and plans to phase them out globally by the end of 2024.
• • an early example of a company looking at a nonfluorinated alternative. It introduced Kynar 500 FSF, a line of PVDF polymers made with nonfluorinated surfactants, in 2008, when most of the industry was just beginning to convert from one fluorosurfactant to another.

5. Solvay:

• • wants to phase out fluorosurfactants by 2026.
• • In 2019, it quadrupled R&D spending on nonfluorinated polymerization technology and now has over 100 scientists dedicated to the effort.
• • In June 2021, it stopped using fluorosurfactants to produce PVDF at its plant in West Deptford, New Jersey.
• • the main breakthrough was modifying the process conditions in the reactor. Solvay won’t disclose which molecule replaced the fluorinated surfactant, but he says it is a nonfluorinated material that has been used “widely in many industries for many, many decades.”
• • The PVDF that Solvay made using the modified process had to be tested with clients. “At almost every customer, we had success,” Finelli says, adding that a few customers had to make some processing changes to use the modified polymer.
• • about 90% of the company’s PVDF output uses a suspension process that doesn’t require fluorinated surfactants. Products made using that process tend to go into higher-end applications, such as batteries.
• • according to Finelli: “The higher the molecular weight, the higher the fluorine content, the harder the challenge,” he says. “That’s why, when we looked at our portfolio, we had a road map for almost everything but PTFE and high-fluorine PFA—these polymers in our mind would have taken too long.” **GFL has a break through in this in both PTFE and PFA **

6. Officials at fluoropolymer companies are quick to point out clean energy and high-tech sectors that couldn’t manage without the polymers. “Fluoropolymers are the key membrane that splits H2O into H and O. That’s how you make green hydrogen. And in a fuel cell, that same fluoropolymer recombines the hydrogen with oxygen to generate electricity.”
7. Chemours:

• • perfluoroalkyloxy alkane (PFA) copolymer tubes and fittings that semiconductor fabricators use to carry aggressive and high-purity fluids like hydrofluoric acid. “You need the chemical inertness, and you need the purity for these semiconductor chips.
• • Much of Chemours’s Viton FKM fluoroelastomer line has been made without fluorosurfactants for about 20 years.
• • PTFE and other product lines for which the firm hasn’t found an alternative surfactant, it has favored a strategy of abating the fluorosurfactant emissions and thermally destroying the rest. “A nonfluorinated surfactant is not the ultimate solution,”

8. Ever since fluoropolymers were introduced, in the middle of the 20th century, making many of them has required using fluorosurfactants. These processing aids are critical to the emulsion polymerization process, in which a polymer is built in water from fluorinated monomers. The surfactant stabilizes the growing emulsion particle during polymerization, so you don’t get agglomeration or coagulation. When the polymerization is done, the surfactant is washed out of the polymer mixture, but some residual surfactant remains. Fluorosurfactants have minimal impact on the polymer’s final properties, he says.

9. The task is trickier than merely swapping one fluorinated surfactant for another, Gaboury says. “It’s relatively easy to make the emulsion polymer with a nonfluorinated surfactant,” he says. “It’s difficult to make products with a nonfluorinated surfactant that have the same performance profile at the very end. When chemists change to a nonfluorinated surfactant, they usually change other ingredients as well, such as the initiator and the transfer agent. “You have a little bit different profile of reactor materials, and ultimately there’s a little bit different residual profile in the product.” That can cause performance problems.

10. new surfactants are typically hydrocarbon-based. But the hydrogen-carbon bond isn’t as strong as the fluorine-carbon bond. “The presence of that hydrogen results in side reactions that you don’t want when you’re making a fluoropolymer.

11. PTFE is made with a highly reactive monomer, tetrafluoroethylene, that creates many unintended fluorinated by-products. Chemours hasn’t found fluorosurfactant alternatives for PTFE or for similar polymers such as fluorinated ethylene propylene and PFA copolymers that don’t result in such by-products.