Enhancing the processability of polychlorotrifluoroethylene via copolymerization with perfluoropropyl vinyl ether

Abstract

Polychlorotrifluoroethylene (PCTFE) is an early commercial fluoropolymer with outstanding properties, but its high melt viscosity and poor thermal stability limit its processability and development. However, traditional modification methods often compromise the inherent advantages of the material, which affects its performance. Fortunately, inspired by the copolymerization of tetrafluoroethylene, this study modified PCTFE by incorporating a small amount of perfluoropropyl vinyl ether (PPVE). After copolymerization with PPVE, the structural regularity of the molecular chains is reduced, the length of crystalline segments is shortened, and chain mobility is enhanced. These changes suppress crystallization, lowering the melting point from 213.7 °C to 200.9 °C and reducing melt viscosity from 6.5 × 10³ Pa s to 2.5 × 10³ Pa s. Besides, the mechanical properties of the copolymers were also changed, with the elongation at break increasing from 4.4% to 40.4%, Young's modulus decreasing from 1.14 GPa to 0.58 GPa, and tensile toughness increasing from 0.86 MJ m⁻³ to 11.50 MJ m⁻³. Crucially, both the thermal stability and dielectric properties of the material remain unaffected, which not only broadens the processing window but also further expands its potential application fields.