ISSN:
0887-624X
Keywords:
plasma copolymerization
;
ethylene
;
tetrafluoroethylene
;
infrared spectroscopy
;
x-ray photoelectron spectroscopy
;
copolymer deposition rates
;
mechanism
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The plasma copolymerization of ethylene (ET) and tetrafluoroethylene (TFE) was investigated by means of IR and XPS analyses. The deposition rates for plasma ET/TFE copolymers, when plotted versus mol % TFE in the feed gas, gave a concave-downward curve situated above the straight-line joining the deposition rates for the respective plasma polymers, PPET and PPTFE, with the maximum rate at ∼ 70-80 mol % TFE. This result, coupled with the finding that normalized absorbances of the C=H and C=F IR bands of ET/TFE copolymers had maxima at ∼ 20 and 80 mol % TFE, respectively, indicated a positive interaction between ET and TFE such that each monomer “sensitized” the plasma copolymerization of the other. As analyzed by XPS, CF groups dominated over CF2 and CF3 groups at 5-70 mol % TFE, but at ≥ 80 mol % TFE, these moieties approached the relative proportions in PPTFE (CF2 〉 CF3 〉 CF). The plot of F/C ratio versus mol % TFE was concave-upward and situated below the hypothetical straight-line plot representing noninteracting, independent polymerization of ET and TFE, while the % F in the plasma copolymers was linear with mol % TFE. The F1s mean binding energies of the ET/TFE plasma copolymers, which increased monotonically with % F, were consistently higher than those for several commercial polymers of fluorinated olefins at comparable values of % F. This result suggested clustering of CFn moieties in the plasma copolymers or the presence of F atoms in highly fluorinated environments. © 1992 John Wiley & Sons, Inc.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pola.1992.080301303
