Thermoplastic and spectroscopic properties of amorphous fluoropolymer thin films

An Ultrastable Polymeric Glass: Amorphous Fluoropolymer with Extreme Fictive Temperature Reduction by Vacuum Pyrolysis

“…The glass transition temperature ( T g ) of the powder form of Teflon AF 1600 was determined from the limiting fictive temperature ( T f ′ ) measured by conventional differential scanning calorimetry (DSC, Q20 Calorimeter from TA Instruments) with 10 K/min cooling and heating rates. The measured T g was 160 °C, consistent with the reported values from the manufacturer and also from several other studies. − , Vapor pyrolysis deposition was used to produce 300 to 700 nm thick stable films following the procedures of Ediger and co-workers − in their work on small molecule glass-formers. The Teflon AF 1600 was directly deposited onto silicon wafers or onto the back sides (silicon dioxide) of the Flash DSC chips under 10 –7 Torr vacuum using a Varian high vacuum evaporator (Varian 3118).…”

“…Several studies have reported a composition change due to pyrolysis of amorphous Teflon during VPD experiments. For instance, Nason and co-workers , observed a decrease of dioxole content during VPD of a Teflon AF 1600 film. In addition, Chow et el, observed an increase of dioxole content in a VPD Teflon AF 2400 film, but they did not observe a composition change for Teflon AF 1600.…”

“…However, there are no reports of ultrastable polymeric glasses even though it is known that polymers, in special conditions, can be successfully vapor deposited, − though the extremely low vapor pressures of polymers generally can be problematic. Hence, pyrolysis of the chain and repolymerization may be the route of deposition. ,, In the current work, we have used a vacuum pyrolysis deposition (VPD) method to produce stable polymeric glasses using an amorphous fluorinated copolymer.…”

“…Hence, pyrolysis of the chain and repolymerization may be the route of deposition. ,, In the current work, we have used a vacuum pyrolysis deposition (VPD) method to produce stable polymeric glasses using an amorphous fluorinated copolymer. There are reports − that amorphous fluorinated copolymers can be made into amorphous thin films by physical vapor deposition through a process in which the amorphous Teflon pyrolyzes into a sufficiently low molecular weight vapor phase and repolymerizes on to the substrate during the deposition process. In these studies the deposition substrates were at room temperature. − For instance, Moore and co-workers , reported that Teflon AF 1600 films were produced by a physical vapor deposition-like (vacuum pyrolysis) process while Nason and co-workers , reported similarly that both Teflon AF 1600 and 2400 thin films could be made into PVD-like films.…”

“…There are reports − that amorphous fluorinated copolymers can be made into amorphous thin films by physical vapor deposition through a process in which the amorphous Teflon pyrolyzes into a sufficiently low molecular weight vapor phase and repolymerizes on to the substrate during the deposition process. In these studies the deposition substrates were at room temperature. − For instance, Moore and co-workers , reported that Teflon AF 1600 films were produced by a physical vapor deposition-like (vacuum pyrolysis) process while Nason and co-workers , reported similarly that both Teflon AF 1600 and 2400 thin films could be made into PVD-like films. In these instances, no evidence was reported for the creation of stable glasses, undoubtedly because the purpose of the studies was different from the present work.…”