Fluoropolymers after PFAS: Mechanical and rheological comparisons of PVDF‐CTFE polymers

Abstract Due to their environmental and health impacts, the increasing need to eliminate perfluoroalkyl substances (PFAS) has driven the exploration of alternative synthetic routes for fluoropolymers. This study investigates the mechanical and rheological properties of poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) (PVDF‐CTFE) synthesized using traditional PFAS‐based methods and new “no added PFAS” approaches. Various synthesis parameters such as reaction temperature, agitation speed, and initiator concentration were varied to produce several polymer lots. The resulting PVDF‐CTFE polymers were evaluated by gel permeation chromatography, rheology, and tensile testing to assess various replacements for the legacy (i.e., added PFAS) material. Our findings indicate that the “no added PFAS” PVDF‐CTFE can achieve mechanical and rheological performance comparable to traditional methods, with certain lots (i.e., 2059) closely matching the legacy lot (i.e., 30035) due to its relatively low molecular weight when compared with other lots. The tensile strength, elongation, and viscoelastic properties from tensile testing, in‐situ pressure monitoring during compounding, and parallel plate rheology all agreed that due to its relatively low molecular weight, lot 2059 was the most appropriate replacement for 30035. This work provides a foundational understanding of how synthesis variations to eliminate added PFAS can be tuned to create materials with similar properties as those made with PFAS, guiding future developments in environmentally safer fluoropolymer production. Highlights PFAS‐free PVDF‐CTFE evaluated. Mechanical properties approached PVDF‐CTFE made with PFAS. Varied synthesis impacts assessed. Guides eco‐friendly polymer production.