Characterization of polyethylene surfaces heated after plasma fluorination

Abstract

Plates of polyethylene with ultrahigh molecular weight (PEUHMW) were treated by radiofrequency capacitive CF4 plasma discharge in order to incorporate fluorinated functional groups. The consequences of subsequent heating treatments after fluorination were investigated by the combined use of angle‐resolved XPS characterizations and measurements of surface free energy γs . The temperature range explored covers the zone from room temperature to 240 °C. After the CF4 plasma treatments, the incorporation of CF x groups at the surface of PEUHMW induces a decrease of the γs value. Further thermal treatments lead to modifications of the chemical surface composition and of γ s . The most important changes concern a significant increase of the surface free energy, where the contribution of the dispersive component is the most affected, and a decrease of the F/C ratio. The fluorine departure is caused by chain scission in the polymer and is accompanied by a surface oxidation, as revealed by the O 1s peak intensity increase. Copyright © 1999 John Wiley & Sons, Ltd.

LDPE Surface Modifications Induced by Atmospheric Plasma Torches with Linear and Showerhead Configurations

“…For this reason, the analysis depth ( z ) is calculated from the following equation, according to which z = 2.8 λ for TOA = 75°, while z = 0.8λ for TOA = 15° . Table represents the analysis depths (nm) calculated from the equation by considering that the intensity on the top surface (with TOA equal to 15°) is the reference intensity, as the XPS analyzer limits are 15 and 75°: …”

Understanding polyethylene surface functionalization by an atmospheric He/O2plasma through combined experiments and simulations

“…For this reason, the analysis depth (z) is calculated from equation (1), according to which z = 2.8λ for TOA = 75°, while z = 0.8λ for TOA = 15° [24,25]. Table 2 represents the analysis depths (nm) calculated from equation (1) by considering that the intensity on the top surface (with TOA equal to 15°) is the reference intensity, since the XPS analyser limits are 15° and 75° [26,27]: z(nm) = 3 · λ · sin(TOA). (1) A PRE-PRINT VERSION.…”

Aging behavior of oxygen plasma-treated polypropylene with different crystallinities

“…The operating pressure during analysis was in the range of 10 −9 Torr. Angle-resolved XPS measurements were carried out at take-off angles of 20 • (3.4 nm depth) and 90 • (10 nm depth) for depth profiling of the treated surfaces both before and after aging, and sampling depth for each take-off angle was calculated from equation (2) [1,16,17]:…”