TY - JOUR A1 - Gross, Thomas A1 - Kühn, Gerhard A1 - Unger, Wolfgang T1 - Photoelectron spectroscopy on organic surfaces: X-ray degradation of oxygen-plasma-treated and chemically reduced poly(propylene) surfaces in comparison to conventional polymers N2 - The X-ray-induced sample damage during mono XPS analysis of an oxygen-plasma-oxidized and subsequently wet-chemically reduced poly(propylene) film was investigated as a showcase for plasma-modified or plasma-deposited samples. By doing this, the degradation index approach as introduced by Beamson and Briggs in the Scienta ESCA300 high-resolution XPS database of organic polymers has been adopted. As to be expected, the sample degrades by loosing oxygen as revealed by observation of decreasing O/C and COR/Csum ratios. However, the X-ray degradation indices are definitely higher than those of conventional reference polymers. Moreover, the COR/Csum degradation index is significantly higher in comparison with one obtained for the O/C ratio. In that context, there is no difference between the plasma sample and a conventional poly(vinyl alcohol) polymer. It is concluded that for reliable quantitative surface chemical analysis, the quality of spectra in terms of acquisition times must be optimized aimed to a minimization of X-ray degradation. Finally, it is proposed to describe the photon flux of an X-ray gun in an XPS experiment, which defines the degradation rate at the end, by using the sample current simply measured with a carefully grounded sputter-cleaned reference silver sample. KW - Photoelectron spectroscopy KW - ESCA/XPS KW - Surfaces KW - Surface modification KW - Poly(propylene) (PP) KW - Plasma treatment KW - X-ray KW - Degradation PY - 2009 DO - https://doi.org/10.1002/sia.3024 SN - 0142-2421 SN - 1096-9918 VL - 41 IS - 5 SP - 445 EP - 448 PB - Wiley CY - Chichester AN - OPUS4-19252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schartel, Bernhard A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Surface Controlled Fire Retardancy of Polymers Using Plasma Polymerisation N2 - Communication: Fire retardant coatings are deposited on polyamide-66 using plasma polymerisation. Chemical composition and thickness of deposits are adjusted varying the plasma treatment based on hexamethydisiloxane mixed with oxygen. The fire retardancy performances are evaluated using a cone calorimeter. The correlation between fire retardancy and thickness as well as chemical composition is discussed. KW - Cone calorimeter KW - Flame retardance KW - Heat release KW - Plasma polymerization KW - Polyamides PY - 2002 DO - https://doi.org/10.1002/1439-2054(20020901)287:9<579::AID-MAME579>3.0.CO;2-6 SN - 1438-7492 SN - 1439-2054 VL - 287 IS - 9 SP - 579 EP - 582 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-1537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Koprinarov, Ivaylo A1 - Kühn, Gerhard A1 - Weidner, Steffen A1 - Vogel, Lydia T1 - Chemical reactions at polymer surfaces interacting with a gas plasma or with metal atoms - their relevance to adhesion N2 - The chemical and morphological stabilities of polymer segments in the near-surface layer were investigated by spectroscopic methods such as X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy. Model studies were undertaken with Langmuir–Blodgett films, self-assembled monolayers and oligomer films. For thin polymer layers (30 to 500 nm), the changes in molecular-weight distributions of some polymers were investigated systematically by size exclusion chromatography, matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry and thermal-field flow fractionation for oxygen- and helium-plasma exposures. The polymer surfaces were found to be relatively stable at exposure to an oxygen low-pressure plasma up to ca. 2 s. This is important information to get maximum adhesion to metals in composites. In correlation to their redox potentials, potassium, aluminium and chromium react with oxygen functional groups at the polymer/metal interface. In a dedicated study, chromium was found to attack aromatic rings and form different reaction products. PY - 1999 DO - https://doi.org/10.1016/S0257-8972(99)00229-7 SN - 0257-8972 VL - 116-119 SP - 772 EP - 782 PB - Elsevier Science CY - Lausanne AN - OPUS4-6981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Unger, Wolfgang T1 - Formation of Plasma Polymer Layers with Functional Groups of Different Type and Density at Polymer Surfaces and their Interaction with Al Atoms N2 - Monotype functionalizations with different types of functional groups (OH, NH2, COOH) on polypropylene and poly(tetrafluoroethylene) surfaces were synthesized using pulsed plasma-initiated homo- or copolymerization of functional group-carrying monomers. The maximum concentrations of functional groups were 31 OH, 18 NH2 or 24 COOH groups per 100 C atoms using allyl alcohol, allylamine or acrylic acid respectively as the monomer. The measured peel strengths of aluminium deposits increased linearly with the concentration of functional groups. Near the maximum concentration of OH (>27 OH/100 C atoms) or at moderate concentrations of COOH groups (>10 COOH/100 C atoms), constant (maximum) peel strengths were measured due to the mechanical collapse of one component in the composite (cohesive failure). Interface failures in Al-PP composites were found with COOH, NH2 and OH groups and cohesive failures were seen when higher concentrations of COOH groups were applied (>10 COOH/100 C atoms). PY - 2004 DO - https://doi.org/10.1002/ppap.200400008 SN - 1612-8850 SN - 1612-8869 VL - 1 IS - 1 SP - 28 EP - 50 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-4707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Geng, Sh. A1 - Koprinarov, Ivaylo A1 - Kühn, Gerhard A1 - Weidner, Steffen T1 - Modelling plasma-induced reactions on polymer surfaces using aliphatic self-assembling and LB layers PY - 1998 SN - 0257-8972 VL - 98 SP - 1132 EP - 1141 PB - Elsevier Science CY - Lausanne AN - OPUS4-6999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Friedrich, Jörg Florian A1 - Kühn, Gerhard A1 - Mix, Renate A1 - Retzko, Iris A1 - Gerstung, Vanessa A1 - Weidner, Steffen A1 - Schulze, Rolf-Dieter A1 - Unger, Wolfgang ED - Mittal, K. L. T1 - Plasma polymer adhesion promoters for metal-polymer systems T2 - 2nd International Symposium on Polyimides and Other High Temperature Polymers: Synthesis, Characterization and Applications CY - Newark, NJ, USA DA - 2001-12-03 KW - r.f. pulsed plasma KW - Plasma polymers with functional groups KW - Copolymers KW - Adhesion promoting interlayers KW - Metal-polymer systems PY - 2003 SN - 90-6764-378-5 VL - 2 SP - 359 EP - 388 PB - VSP CY - Utrecht AN - OPUS4-6967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weidner, Steffen A1 - Kühn, Gerhard A1 - Roessner, D. A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas ED - Olefjord, I. ED - Nyborg, L. ED - Briggs, D. T1 - Changes in molecular weight distribution of polymers by plasma treatment T2 - 7th European Conference on Applications of Surface and Interface Analysis CY - Göteborg, Sweden DA - 1997-06-16 PY - 1997 SN - 0-471-97827-2 SP - 795 EP - 799 PB - Wiley CY - Chichester AN - OPUS4-6997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weidner, Steffen A1 - Kühn, Gerhard A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas T1 - Plasmaoxidative Degradation of Polymers Studied by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry PY - 1996 SN - 0951-4198 SN - 1097-0231 VL - 10 SP - 727 EP - 732 PB - Wiley CY - Chichester AN - OPUS4-7004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Friedrich, Jörg Florian A1 - Retzko, Iris A1 - Kühn, Gerhard A1 - Unger, Wolfgang A1 - Lippitz, Andreas ED - Mittal, K. T1 - Metal doped plasma polymer films T2 - 7th Symposium on Metallized Plastics CY - Newark, NJ, USA DA - 1999-12-02 KW - Plasma polymer KW - r.f. pulsed plasma KW - Conducting films KW - Metal-polymer interface PY - 2001 SN - 90-6764-340-8 VL - 7 SP - 117 EP - 142 PB - VSP CY - Utrecht AN - OPUS4-929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Friedrich, Jörg Florian A1 - Unger, Wolfgang A1 - Lippitz, Andreas A1 - Koprinarov, Ivaylo A1 - Ghode, Archana A1 - Geng, Sh. A1 - Kühn, Gerhard T1 - Plasma-based introduction of monosort functional groups of different type and density onto polymer surfaces. Part 1: Behaviour of polymers exposed to oxygen plasma N2 - Several approaches were investigated to produce monosort functionalized polymer surfaces with a high density and homogeneity of functional groups: (i) Plasma oxidation followed by wet-chemical reduction, (ii) formation of radicals and grafting on of functional group carrying molecules, (iii) plasma bromination followed by (iv) Williamson or Gabriel-like synthesis of spacer molecules, and (v) a pulsed plasma polymerization of functional groups bearing monomers or (vi) their copolymerisation with other comonomers. The formation of hydroxyl (OH), primary amino (NH2), and carboxyl (COOH) groups was studied in detail. The oxygen plasma treatment (i) in a low-pressure non-isothermal glow discharge results in the formation of a wide variety of O functional groups, polymer degradation and crosslinking. Low power densities and short exposure times (0.1 to 2 s) are required to functionalize a surface while preserving the original polymer structure. Carbonate, ester, and aromatic groups are rapidly degraded by an oxygen plasma treatment leading to scissions of polymer backbones and loss in molecular weight. Also the formation of macrocycles and C=C bonds was observed in a region of around 4 nm in depth. The investigated polymers could be classified by their degradation behaviour on exposure to the oxygen plasma.___TAGSTART___BR___TAGEND___ In order to maximize the process selectivity for OH groups, the variety of oxygen functionalities formed by the oxygen plasma was wet-chemically reduced by diborane, vitridetrade (Na complex), and LiAlH4. Typical yields were 9 to 14 OH groups per 100 carbon atoms.___TAGSTART___BR___TAGEND___ Plasma bromination (iii) (40 Br per 100 C atoms) of polymers, followed by grafting of spacer molecules (iv), has been proved to be a highly selective reaction.___TAGSTART___BR___TAGEND___ Another way to produce high densities of monosort functionalities was the pulsed plasma polymerization of functional group bearing monomers such as allylamine, allylalcohol or acrylic acid (v). The retention of chemical structure and functional groups during plasma polymerization was achieved by using low power densities and the pulsed plasma technique. The maximum yields were 30 OH, 18 NH2, and 24 COOH groups per 100 C atoms. To vary the density of functional groups a chemical copolymerization with ''chain-extending'' comonomers such as butadiene and ethylene was initiated in the pulsed plasma (vi). Additionally, the often-observed post-plasma oxidations of such layers initiated by reaction of trapped radicals with oxygen from the air were successfully suppressed by using NO gas as radical quencher. PY - 2003 DO - https://doi.org/10.1163/156855403765826865 VL - 10 IS - 2-3 SP - 139 EP - 171 PB - North-Holland CY - New York, NY AN - OPUS4-2705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kühn, Gerhard A1 - Ghode, Archana A1 - Weidner, Steffen A1 - Retzko, Iris A1 - Unger, Wolfgang A1 - Friedrich, Jörg Florian ED - Mittal, K. L. T1 - Chemically well-defined surface functionalization of polyethylene and polypropylene by pulsed plasma modification followed by grafting of molecules T2 - 2nd International Symposium on Polymer Surface Modification: Relevance to Adhesion CY - Newark, NJ, USA DA - 1999-05-24 KW - Plasma modification KW - Chemical conversion of functional groups KW - Spacers KW - Polypropylene KW - Polyethylene PY - 2000 SN - 90-6764-327-0 VL - 2 SP - 45 EP - 64 PB - VSP CY - Utrecht AN - OPUS4-6975 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Friedrich, Jörg Florian A1 - Mix, Renate A1 - Kühn, Gerhard A1 - Unger, Wolfgang T1 - Functional groups bearing plasma homo and copolymer layers as adhesion promoters in metal-polymer composites T2 - 10. Neues Dresdner Vakuumtechnisches Kolloquium (NDVaK) CY - Dresden, Germany DA - 2002-10-17 PY - 2002 SP - 6 EP - 15 PB - DTVa CY - Dresden AN - OPUS4-6970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -