Recycling Tetrafluoroethylene–Perfluoroalkyl Vinylether Copolymer (PFA) Using Extrusion Process

Abstract

Tetrafluoroethylene–perfluoroalkyl vinylether copolymer (PFA) has a broad application ranging from biomedical and aerospace to corroding environments in the chemical industry. Despite a low share in end‐of‐life products, PFA processing can produce up to 30% of waste. Thus, understanding how recycled fluorinated polymers affect product performance is crucial to ensure primary recycling, besides economic and environmental reasons. In this paper, the utilization feasibility of PFA waste materials is investigated, i.e., recycled PFA (PFAr) in closed‐loop recycling. The effect of PFAr loading (5–100 wt.%) on the thermal, mechanical, rheological, and color properties and chemical resistance are studied. Thermal properties and chemical resistance showed no significant changes in all ranges of PFAr content tested. The addition of higher loads of PFAr (≥50 wt.%) leads to a reduction in mechanical properties, particularly stress‐strength analysis and elongation at break. However, elastic modulus and hardness have improved concurrently with an increase in the degree of crystallinity. The decrease in complex viscosity and yellowing of the samples occurred probably induced by a polymer chain degradation. Despite that, the addition of up to 10 wt.% of PFAr proved to be an effective alternative to reusing PFA residues based on mechanical recycling.

Recycling and the end of life assessment of fluoropolymers: recent developments, challenges and future trends

“…, PTFE), FEP, PFA and PVDF waste or scraps generated during production has already been achieved ( e.g. , by Dyneon on a pilot scale, 52 at Karlsruhe Institute of Technology, 72 or by Arkema company 53,54 ), that of FPs in consumer articles is not well established, given that these FPs are typically contaminated by other fillers and substances, which makes their recycling difficult. Moreover, the very slow decomposition of PTFE occurs above the application temperature of 260 °C for months.…”

“…Considering their annual plastic production of more than 460 million tonnes, 1 only 9% has been recycled, 46,48 while that percentage was only 3.4% for FPs (yearly production of 320,300 tonnes in 2018). 9,199 Although the recycling of clean FPs (e.g., PTFE), FEP, PFA and PVDF waste or scraps generated during production has already been achieved (e.g., by Dyneon on a pilot scale, 52 at Karlsruhe Institute of Technology, 72 or by Arkema company 53,54 ), that of FPs in consumer articles is not well established, given that these FPs are typically contaminated by other fillers and substances, which makes their recycling difficult. Moreover, the very slow decomposition of PTFE occurs above the application temperature of 260 1C for months.…”

“…However, the elastic modulus and hardness improved with an increase in the degree of crystallinity. Romoaldo et al 52 noted a decrease in viscosity and yellowing of the samples, which are probably linked to the polymer chain degradation. Nevertheless, the addition of up to 10 wt% of PFAr proved to be an effective alternative to reuse PFA residues based on mechanical recycling.…”

“…Thus, understanding how recycled FPs affects the performance of products is essential to ensure primary recycling, besides economic and environmental reasons. Romoaldo et al 52 used the feasibility of PFA waste materials to study recycled PFA (PFAr) in closed-loop recycling. They studied the effect of PFAr loading (5-100 wt%) in virgin PFA on the thermal, mechanical, and rheological properties, color and chemical resistance, with the latter two showing no significant changes in the range of PFAr content tested.…”

Advancing Plastic Recycling: Challenges and Opportunities in the Integration of 3D Printing and Distributed Recycling for a Circular Economy

“…The flexibility of injection molding enables the production of complex shapes and sizes, making it suitable for a wide range of plastic products. Through the utilization of recycled plastic and injection molding, this approach has the potential to make a significant difference in waste reduction and promote a more sustainable environment [158].…”