Biaxially stretched polypropylene (PP) foils treated with oxygen plasma at low pressure were analysed by core level and valence band region X-ray photoelectron spectroscopy (XPS), atomic force microscopy and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Applying short treatment times the XPS O~C atomic ratios are ~<0.1. Valence band electron spectroscopy for chemical analysis (ESCA) and NEXAFS spectroscopy reveal that a certain number of C-O and a smaller amount of C--O functionalities together with C=C bonds exist at a short-time treated PP surface. These species were not observed or resoh'ed by a standard core level XPS analysis of the same surface. The surface is smoothed by the plasma treatment and the C-O and C~O bonds are slightly non-statistically oriented (parallel to the surface plane). Considering the results obtained after prolonged plasma treatment, NEXAFS spectroscopy provides a direct indication for the formation of conjugated carbon double bonds in the surface region of the PP samples. (Keyw'ords: polypropylene; plasma treatment; spectroscopy)
Посилання на статтю:
Valence band region XPS, AFM and NEXAFS surface analysis of low pressure d.c. oxygen plasma treated polypropylene / Th. Gross, A. Lippitz and W. E. S. Unger // Polymer. – 1994. – Vol 35. – P. 5590-5594.