Portal de Periódicos da CAPES

Chemical surface treatment of poly(tetrafluoroethylene) powder

1993; Wiley; Volume: 209; Issue: 1 Linguagem: Inglês

10.1002/apmc.1993.052090102

1522-9505

Chi‐Yuan Huang, Wen‐Yen Chiang,

Silicone and Siloxane Chemistry

Abstract Poly(tetrafluoroethylene) powder has been treated with sodium‐naphthalene complex in tetrahydrofuran (THF) to improve its surface properties. The cryocondition (−40°C) was taken to keep the active species alive so that the PTFE powder surface could be etched homogeneously and a large area of PTFE could be etched. The Na‐treated PTFE powder was examined by IR, ESCA (electron spectroscopy for chemical analysis), X‐ray diffractometry, thermal analysis and SEM (scanning electron microscopy). IR spectra showed that the surface structure of Na‐treated PTFE powder possessed a lot of CFCF− double bond structures. ESCA surface analyses also revealed the formation of CFCF− double bonds. During the process of sodiumnaphthalene complex etching, most of NaF salt formed was adsorbed on the surface of treated PTFE (CPTFE, NaF adsorbed) and a small amount of NaF salt was found doped into treated PTFE. As a result, part of the surface of treated PTFE was found doped into treated PTFE. As a result, part of the surface of treated PTFE was similar to a free alkali‐fluoride‐doped polyfluoroacetylene. It was shown by SEM that the etched PTFE had a web‐like surface.