TY - JOUR A1 - Mix, Renate A1 - Gähde, J. A1 - Goering, Harald A1 - Schulz, Günter T1 - Segmented polyurethanes with 4,4-bis-(6-hydroxyhexoxy)biphenyl as chain extender - Part 2. Synthesis and properties of MDI-polyurethanes in comparison with 2,4-TDI-polyurethanes N2 - Linear segmented polyurethanes based on poly(butylene adipate)s (PBA) of different molecular weight (Mn 2000, 1000, and 600), 4,4-diphenylmethane diisocyanate (MDI) and the mesogenic diol 4,4-bis-(6-hydroxyhexoxy)biphenyl (BHHBP) as well as the unsegmented polyurethane consisting of MDI/BHHBP units have been synthesized and characterized by elemental analysis, 13C-NMR and SEC. The thermal behavior and the morphology were studied by DSC, polarizing microscopy, and DMA. The properties of the MDI-polyurethanes were discussed in relation to the BHHBP chain extended 2,4-TDI-polyurethanes and common 1,4-butanediol chain-extended MDI products. MDI polyurethanes based on PBA (Mn 2000) exhibit a glass transition temperature Tg of about -40°C independent of the hard segment content up to 50% hard segments. At higher hard segment contents increasing Tgs were observed. Polyurethanes, based on the shorter polyester soft segments PBA (Mn 1000 or 600), reveal an increase in the glass transition temperatures with growing hard segment content. The thermal transitions caused by melting of the MDI/BHHBP hard segment domains are found at 50 K higher temperatures in comparison with the analogous TDI products with mesogenic BHHBP/TDI hard segments. Shortening of the PBA chain length causes a shift of the thermal transitions to lower temperatures. Polarizing microscopy experiments indicate that liquid crystalline behavior is influenced by both the content of mesogenic hard segments and the chain length of the polyester. © 1996 John Wiley & Sons, Inc. PY - 1996 U6 - https://doi.org/10.1002/(SICI)1099-0518(19960115)34:1<33::AID-POLA3>3.0.CO;2-4 SN - 0360-6376 SN - 0887-624X VL - 34 IS - 1 SP - 33 EP - 44 PB - Wiley CY - Hoboken, NJ AN - OPUS4-2151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gähde, J. A1 - Mix, Renate A1 - Krüger, Ralph-Peter A1 - Goering, Harald A1 - Funke, W. A1 - Hermann, U. T1 - Adherence of Liquid Crystalline TDI-Polyurethanes to Steel KW - Main-chain liquid crystalline polyurethanes KW - Primer on steel KW - Pull-off test KW - Wet adhesion of alkyd melamine resin KW - Mesogenic unit KW - Glass transition temperature KW - Hard segments KW - Soft segments PY - 1996 SN - 0021-8464 SN - 1545-5823 VL - 58 SP - 243 EP - 251 PB - Gordon & Breach CY - New York, NY AN - OPUS4-2152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Schimanski, A. A1 - Sturm, Heinz A1 - Mix, Renate A1 - Illenberger, E. T1 - Surface Modification of Polyamides by Direct Fluorination N2 - Bulk samples and thin films of polyamides (PA6 and PA12) were exposed to fluorine (1 - 10 vol.-% F2 in N2) and analysed with photoelectron (XPS) and infrared spectroscopy. Fluorination affects both, the amide and the hydrocarbon parts of the polymers. However, only the carbon atom next to the carbonyl is readily fluorinated. Chemical modification of the amide group is apparent in a large binding energy shift (+5 eV) of the N1s level and the appearance of a CO band at 1734 cm-1. It is concluded that the amide C-N bond is cleaved in the fluorination process and that COOH and NF2 end groups are formed. This conclusion is corroborated by the appearance of ester oxygen in the XPS and by the 19F NMR spectra of the volatile products that show fluorine signals chemically shifted about 200 ppm towards lower field as compared with the CHF environment. KW - Gasfluorierung KW - IR KW - XPS KW - AFM KW - NF2-Gruppe PY - 2004 UR - http://www.e-polymers.org SN - 1618-7229 IS - 8 SP - 1 EP - 16 PB - De Gruyter CY - [S.l.] AN - OPUS4-3425 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 U6 - 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 - Mix, Renate A1 - Kühn, Gerhard T1 - Functional groups bearing plasma homo and copolymer layers as adhesion promoters in metal-polymer composites N2 - Functional groups bearing monomers were pulsed plasma polymerised with a degree of retained functional groups of 55–91%. The following functional groups could be produced at a maximum of: 30 OH, 18 NH2, and 24 COOH per 100 C atoms. A plasma-initiated radical copolymerisation could also be realised using the functional group bearing monomers as a source of functionalities, olefins as ‘chain-extenders’ and dienes as ‘chemical cross-linkers’. The peel strengths of Al layers on such plasma polymers were correlated to the type and density of functional groups. KW - Functional groups KW - Adhesion promoters KW - Metal-polymer composites PY - 2003 U6 - https://doi.org/10.1016/S0257-8972(03)00350-5 SN - 0257-8972 VL - 174-175 SP - 811 EP - 815 PB - Elsevier Science CY - Lausanne AN - OPUS4-2703 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 - Fritz, Andreas A1 - Schönhals, Andreas T1 - Polymer surface modification with monofunctional groups of variable types and densities N2 - The retention of chemical structure and functional groups during pulsed plasma polymerization was used for producing adhesion-promoting plasma polymer layers with high concentrations of exclusively one kind of functional groups, such as OH, NH2, or COOH. The maximum content of functional groups was 31 OH using allyl alcohol, 18 NH2 using allylamine, or 24 COOH per 100 C atoms using acrylic acid. To vary the density of functional groups, chemical co-polymerization with ethylene as 'chain-extending' co-monomer, or butadiene as 'chemical crosslinker' was initiated in the pulsed plasma. The composition of these co-polymers was investigated by XPS and IR spectroscopy. The concentrations of functional groups were measured by derivatizing with fluorine-containing reagents and using XPS. A set of plasma parameters was found to be a good compromise between a high number of functional groups and complete insolubility in water, ethanol or THF,which is needed for further chemical processing. Here, these monotype-functionalized surfaces were used in metal-polymer systems as adhesion-promoting interlayers to examine the influence of type and density of functional groups on adhesion. As expected, COOH- and OH-group-terminated interlayers showed maximum peel strengths to evaporated aluminium layers. The adhesion increased linearly with the number of OH groups to a maximum at about 27 OH per 100 C atoms. Higher concentrations of OH groups did not increase the peel strength further. KW - Co-polymers KW - Adhesion-promoting interlayers KW - Metal-polymer systems PY - 2003 U6 - https://doi.org/10.1163/156856103322396695 SN - 0169-4243 SN - 1568-5616 VL - 17 IS - 12 SP - 1591 EP - 1617 PB - VNU Science Press CY - Utrecht AN - OPUS4-2704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, Katrin A1 - Resch-Genger, Ute A1 - Mix, Renate A1 - Friedrich, Jörg Florian T1 - Fluorescence Spectroscopic Studies on Plasma-Chemically Modified Polymer Surfaces with Fluorophore-Labeled Functionalities N2 - Molecular engineering of polymer surfaces that includes the attachment of functional molecules to existing or previously generated reactive chemical groups like e.g., - OH, - NH2, or - CHO requires simple strategies and tools for the controlled generation of surface functionalities and their derivatization as well as for their identification and eventually quantification. Here, we systematically investigate the plasma-chemical surface modification of polypropylene films in combination with dansyl labeling chemistry and conventional, yet costly, XPS and highly sensitive fluorescence spectroscopy for the detection of surface groups. Based on these results, the potential of and requirements on the fluorometric characterization and quantification of surfaces functionalities are discussed. KW - Fluorescence spectroscopy KW - Surface functionalization KW - Covalent labeling of polymer surfaces KW - Plasma modification KW - Fluorescent probe PY - 2006 U6 - https://doi.org/10.1007/s10895-006-0076-x SN - 1053-0509 SN - 1573-4994 VL - 16 IS - 3 SP - 441 EP - 448 PB - Plenum Publ. Corp. CY - New York, NY AN - OPUS4-12560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fahmy, A. A1 - Mix, Renate A1 - Schönhals, Andreas A1 - Friedrich, Jörg Florian T1 - Structure of plasma-deposited copolymer films prepared from acrylic acid and styrene: Part I dependence on the duty cycle N2 - Copolymers of acrylic acid and styrene (AA/S) were prepared by pulsed plasma deposition and their structures were studied in dependence on the duty cycle (DC) for a fixed composition of 1:1. As a result, low values of DC doses preserve the structure of monomers in the plasma deposited polymers while high DC leads to a higher degree of fragmentation and a loss in regular structure. Regarding plasma copolymerisation as a feasible method to finish surfaces with a definite number of functional groups it is necessary to characterize both, the chemical nature and the physical properties of the deposited layer. Therefore, a combination of different methods was employed for the characterization of thin plasma copolymer films (FTIR, dielectric spectroscopy, differential scanning calorimetry, X-ray photoelectron spectroscopy (XPS)). Special attention was paid on the unambiguous identification of COOH groups at the surface after derivatization with trifluoroethanol by XPS and in the volume by FTIR. The glass transition temperature of the copolymer system is lower than that for the both plasma deposited homopolymers and increases with the DC in difference to plasma deposited poly(acrylic acid). The dielectric measurements showed that the plasma deposited films were not thermally stable and underwent an undesired post-plasma chemical reaction. The results obtained by dielectric spectroscopy are discussed in detail in comparison with the data from FTIR and XPS measurements. KW - Plasmapolymerisation KW - Copolymerisation KW - Acrylic acid–styrene copolymer KW - Dynamic mobility KW - Plasma copolymerisation KW - Surface functionalization KW - Thin film properties PY - 2012 U6 - https://doi.org/10.1002/ppap.201100117 SN - 1612-8850 SN - 1612-8869 VL - 9 IS - 3 SP - 273 EP - 284 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25654 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mix, Renate A1 - Friedrich, Jörg Florian A1 - Inagaki, N. T1 - Modification of branched polyethylene by aerosol-assisted dielectric barrier discharge N2 - Three polyethylene (PE) types with different branching structures were subjected to air, water and ethanol aerosol-assisted dielectric barrier discharges (DBD) for surface modification. Using the air DBD the incorporated oxygen concentration was found to be independent on the branching of PE in contrast to the introduction of OH groups, which was PE-2 > PE-1 > PE-3. For water-aerosol DBD the succession of OH concentration was in the order of PE-1 > PE-2 > PE-3. Ethanol aerosol-assisted DBD produced the lowest concentration of OH groups also independent on the branching of PE. The chemical nature of introduced oxygen functional groups was inspected by X-ray photoelectron spectroscopy (XPS) and assigned as C–O, >C=O/CHO/O–C–O and O=C–O. KW - PE KW - Surface modification KW - Aerosol-assisted DBD PY - 2012 U6 - https://doi.org/10.1002/ppap.201100052 SN - 1612-8850 SN - 1612-8869 VL - 9 IS - 4 SP - 406 EP - 416 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-25748 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mix, Renate A1 - Hielscher, Stefan A1 - Beck, Uwe A1 - Friedrich, Jörg Florian T1 - Plasma meets chemistry: Combined methods for tailored interface design in metal-polymer composites by selective chemical reactions on plasma modified surfaces N2 - The applicability of polymer-metal composites is mainly determined by the durability of the adhesive strength between both components. Aluminium (Al) deposited on polypropylene (PP) exemplifies different options of interface design. By deposition of plasma polymers on PP the effect of the type of the functionality was investigated. Spacer insertion was accomplished to position the functional group away from the topmost surface. A further kind of interface design involved a partial condensation of functional groups. Hydroxyl and carboxyl groups were most effective to improve adhesion in Al-PP systems. Approximately 7-10 carboxyl or 25-27 hydroxyl groups per 100 C atoms were necessary to increase the peel strength up to ~700 N/m. In this range, the failure of the composite propagated along the interface Al-tape (no peeling of the metal). Spacer molecules between surface and functional groups provoked the effect that the number of needed functional groups for maximum adhesion was strongly reduced. Linking of the functional groups resulted in non-peelable Al-PP laminates. Two adhesion tests were applied - the peel test and the centrifuge technology. For PP foils modified with chemically bonded and additionally linked silanol groups (no peeling) an adhesive strength of (2.5 ± 0.2) N/mm² was determined by centrifuge technology. XPS inspection of both fracture surfaces indicated a sub-surface failure in the polymer. T2 - HTPP-12 - 12th High-tech plasma processes conference CY - Bologna, Italy DA - 2012-06-24 KW - Adhesion PP-Al KW - Modified surfaces KW - Interface design PY - 2012 U6 - https://doi.org/10.1088/1742-6596/406/1/012004 SN - 1742-6588 SN - 1742-6596 VL - 406 SP - 012004-1 - 012004-11 PB - IOP Publ. CY - Bristol, UK AN - OPUS4-28658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -