Melt rheological properties of ETFE: an attempt to illuminate the fluorine-substitution effect

Abstract

Flow behaviors and rheological properties of ethylene tetrafluoroethylene alternating copolymer (ETFE) under high-shear conditions were first reported. Flow instabilities, shear and extensional viscosities, and die swell of ETFE were investigated. Rheological behaviors of perfluorinated ethylene propylene copolymers (FEP), partially fluorinated ETFE, and non-fluorinated polyethylenes (PE) were compared for understanding the role of fluorine incursion on materials properties. It is found that (1) ETFE does not have sharkskin region or second smooth region which frequently occurs in FEP and linear PE; (2) critical shear stresses at which surface melt fracture occurs for the three polymers follow the order: FEP \ ETFE \ PE; (3) stable flow region narrows, die swell weakens, and flow activation energy increases when fluorine content of polymer increases. After time-temperature superposition, shifted shear viscosity, extensional viscosity, and elastic data (die swell) present universal scaling characteristic and superpose well in term of the same shift factors.

The Fabrication of Nanoimprinted P3HT Nanograting by Patterned ETFE Mold at Room Temperature and Its Application for Solar Cell

“…The fluoro-polymer ethylene(tetrafluoroethylene) (ETFE) is a copolymer of ethylene and tetrafluoroethylene and has been attracting more and more attention due to its excellent property [ 16 ]. ETFE material possesses novel toughness, flexibility, and relatively high stiffness ability.…”

“…Thus, the copolymer is widely used in aerospace, nuclear utilization, and solar exploitation areas [ 17 ]. Correspondingly, ETFE films are intensively explored on the molecular parameters and microstructures [ 18 , 19 ], thermal and crystallization behaviors [ 20 , 21 ], and rheology property researches [ 16 , 22 ]. Recently, Chen et al [ 23 ] indicated that the flexible UV transparent ETFE mold could be fabricated by the hot embossing with the HSQ master template and further used to fabricate the OTFT device.…”