CO<sub>2</sub> transport behavior in poly(fluoroalkyl acrylate) and poly(fluoroalkyl methacrylate): a comparative study of fluoropolymer structure-property relationships.

Feng, Sinan; Zhang, Yucheng; Otozawa, Nobuyuki; Murata, Shinichi; Takahara, Atsushi · Soft Matter · 2025

basic_science · Level V

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Abstract

This study examines the CO<sub>2</sub> transport behavior of poly(fluoroalkyl acrylate) (PFA) and poly(fluoroalkyl methacrylate) (PFMA) thin films. Using time-resolved attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) and a quartz crystal microbalance (QCM), we quantified CO<sub>2</sub> diffusivity and solubility, linking these properties to the polymer side-chain architecture. The results demonstrate that PFMA exhibits lower CO<sub>2</sub> permeability than PFA at comparable side-chain lengths, owing to restricted chain mobility caused by the α-methyl backbone of PFMA. Additionally, longer fluorinated side chains increase CO<sub>2</sub> diffusivity while simultaneously reducing solubility owing to weaker polar interactions with CO<sub>2</sub>. Overall, the CO<sub>2</sub> permeability of PFA surpasses that of the PFMA series because of its higher diffusivity. These findings highlight the intricate balance between diffusivity and solubility governed by the molecular structure.