TY - GEN A1 - Janiak, Ch. A1 - Lange, K.C.H. A1 - Marquardt, P. A1 - Krüger, Ralph-Peter A1 - Hanselmann, R. ED - Sun, J. ED - Janiak, C. T1 - Propene and 1-hexene oligomerization with unbridged alkyl-substituted cyclopentadienyl- and phospholyl-zirconium/MAO catalysts - mechanistic implications from oligomer analyses by NMR, SEC, and MALDI-TOF MS PY - 2001 SP - 117 EP - 142 PB - Chemical Industry Press CY - Bejing AN - OPUS4-2193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müeller, W.-D. A1 - Gross, U. A1 - Fritz, Th. A1 - Voigt, Ch. A1 - Fischer, P. A1 - Berger, Georg A1 - Rogaschewski, S. A1 - Lange, K.-P. T1 - Evaluation of the interface between bone and titanium surfaces being blasted by aluminium oxide or bioceramic particles N2 - The surface structure, in particular the surface roughness, and the surface chemistry of titanium implants influence their anchoring in bone. The aim of this study was to analyse metal-bone contact (MBC) after modification of the implant surface, using different materials for blasting. The surface modification of titanium was produced by blasting it with particles made of Al2O3 or bioceramics. The biological effects were then investigated experimentally using 27 rabbits, analysed after 7, 28 and 84 days after the implantation of titanium cylinders treated accordingly. The MBC showed a tendency for more bone after bioceramics were used as a blasting material, compared to Al2O3. KW - Dental implants KW - Surface modification KW - Animal experiment KW - Bioceramics PY - 2003 DO - https://doi.org/10.1034/j.1600-0501.2003.00791.x SN - 0905-7161 SN - 1600-0501 VL - 14 IS - 3 SP - 349 EP - 356 PB - Blackwell Munksgaard CY - Oxford AN - OPUS4-3506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Janiak, Ch. A1 - Lange, K.C.H. A1 - Marquardt, P. A1 - Krüger, Ralph-Peter A1 - Hanselmann, R. T1 - Analyses of Propene and 1-Hexene Oligomers from Zirconocene/MAO Catalysts - Mechanistic Implications by NMR, SEC and MALDI-TOF MS N2 - A series of Cp(C5H5)ZrCl2 and Cp2ZrCl2 pre-catalysts (Cp = C5HMe4, C4Me4P, C5Me5, C5H4tBu, C5H3-1,3-tBu2, C5H2-1,2,4-tBu3) together with (C5H5)2ZrCl2 was used for the directed oligomerization of propene and 1-hexene in comparative experiments. Oligomer characterization was carried out by 1H NMR, SEC (GPC), MALDI-TOF MS, cryoscopy and Raman spectroscopy. From 1H NMR the nature and relative ratio of the double-bond end group is determined together with n if every oligomer molecule contains such a double-bond end group. Normally vinylidene double bonds (from -hydrogen elimination) are found. From 1H NMR and MALDI-TOF MS also vinyl end groups (from -methyl elimination) are observed in the case of oligopropenes with (C4Me4P)- (C5H5)ZrCl2 and with the symmetrical methyl containing Cp2ZrCl2 pre-catalysts. The vinylidene/vinyl ratio depends on the ligand and increases from C5HMe4 (65/35) over C4Me4P (61/39) to C5Me5 (9/91). A comparison of n from 1H NMR and SEC together with MALDI-TOF MS shows that the phospholyl-zirconocenes and (C5HMe4)2ZrCl2 also exhibit chain transfer to aluminium, thereby giving saturated oligomers. KW - Chain transfer KW - MALDI KW - Metallocene catalysts KW - Oligomers KW - Polyolefins PY - 2002 DO - https://doi.org/10.1002/1521-3935(20020101)203:1<129::AID-MACP129>3.0.CO;2-C SN - 1022-1352 SN - 1521-3935 VL - 203 IS - 1 SP - 129 EP - 138 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-2179 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lange, K. T1 - Ultrasound measuring system: Principle and application T2 - Thermosets Conference 2011 - From monomers to components CY - Berlin, Germany DA - 2011-09-21 PY - 2011 AN - OPUS4-24438 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stark, Wolfgang A1 - Teteris, Gundars A1 - Braun, Ulrike A1 - Bohmeyer, W. A1 - Lange, K. T1 - Kontrolle der Vernetzungsreaktion bei reaktiven Harzen - DSC, Rheologie, DMA, FTIR und Online-Ultraschall im Vergleich N2 - Faserverbundbauteile werden durch Tränkung von Fasergewebe mit flüssigem Harz, in der Regel Epoxidharzen, und anschließender Härtung des Harzes gefertigt. Dabei kann man das Gewebe im Vorfeld mit reaktivem Harz tränken und als so genanntes Prepreg verarbeiten oder man injiziert das frisch mit dem Härter gemischte Harz in ein Werkzeug, in dem das Gewebe bereits liegt - z. B. beim RTM-Prozess. Ausgehend von der Aufgabenstellung, eine Prepregherstellung mit hohem Qualitätsstandard zu realisieren und Möglichkeiten der Fertigungskontrolle für den Prepreg-Verarbeiter aufzuzeigen, wurde an einem für die Prepregherstellung vorgesehenen Harzsystem eine weitgehende Charakterisierung des Aushärtungsverlaufs vorgenommen. Wegen der Schwierigkeit, schnell konstante Aushärtungstemperaturen zu erreichen, wurden bei allen Methoden mit einer Heizrate von 1 K/min von RT bis 200 °C aufgeheizt. T2 - Technomer 2011 - 22. Fachtagung über Verarbeitung und Anwendung von Polymeren CY - Chemnitz, Deutschland DA - 10.11.2011 KW - Thermoanalyse KW - Lineare Aufheizung KW - Online Prozesskontrolle KW - Epoxidharz KW - Prepreg PY - 2011 SN - 978-3-939382-10-2 IS - Kap. 1.1 SP - 1 EP - 9 AN - OPUS4-24910 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mantouvalou, I. A1 - Lange, K. A1 - Wolff, Timo A1 - Grötzsch, D. A1 - Lühl, Lars A1 - Haschke, M. A1 - Hahn, Oliver A1 - Kanngießer, B. T1 - A compact 3D micro X-ray fluorescence spectrometer with X-ray tube excitation for archaeometric applications N2 - In this work, the applicability of a new 3D micro X-ray fluorescence (3D Micro-XRF) laboratory spectrometer for the investigation of historical glass objects is demonstrated. The non-destructiveness of the technique and the possibility to measure three-dimensionally resolved fluorescence renders this technique into a suitable tool for the analysis of cultural heritage objects. Although absorption and resolution effects complicate qualitative analysis of the data, layered structures can be distinguished from homogeneous samples without the need for full quantification. Different manufacturing techniques were studied in this work with the help of hand-made reference samples. With the gained knowledge it could be shown for the investigated historical glass object, that black enamel as a stained glass contour colour was used in a cold painting. The object was not fired after the application of the black enamel, but instead the adhesion of the paint was solely provided through organic binding agents and the backing with metal foils. Thus, for the manufacturing of the object, a mixture of cold painting technique with a stained glass color was used. Quantitative measurements with a 3D Micro-XRF setup at the Berlin synchrotron BESSY II confirm the assumptions drawn on the basis of the qualitative investigation with the 3D Micro-XRF spectrometer with X-ray tube excitation. KW - 3D micro XRF KW - Archaeometry KW - Non-destructive testing KW - Cultural heritage PY - 2010 DO - https://doi.org/10.1039/b915912f SN - 0267-9477 SN - 1364-5544 VL - 25 SP - 554 EP - 561 PB - Royal Society of Chemistry CY - London AN - OPUS4-20878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stark, Wolfgang A1 - Jaunich, Matthias A1 - Bohmeyer, W. A1 - Lange, K. T1 - Investigation of the crosslinking behaviour of ehtylene vinyl acetate (EVA) for solar cell encapsulation by rheology and ultrasound N2 - EVA is a widely used material for the encapsulation of photovoltaic modules. It melts at elevated temperatures, and seals the module before it is crosslinked at temperatures above 130 °C by a peroxide-initiated crosslinking reaction. EVA has good optical properties necessary for application in solar modules. For process optimization and quality management, a method for the quick and reliable characterization of EVA crosslinking behaviour is of great value. Here, the practicability of ultrasound for online crosslinking monitoring is demonstrated. A sound velocity increase of about 8 m/s during the crosslinking reaction is found. The ultrasound results are compared with rheometer measurements performed with a curemeter typically used for the investigation of rubber crosslinking. KW - Ethylene vinyl acetate KW - EVA KW - Crosslinking KW - Ultrasound KW - Rheology KW - Curemeter KW - DSC PY - 2012 DO - https://doi.org/10.1016/j.polymertesting.2012.07.004 SN - 0142-9418 VL - 31 IS - 7 SP - 904 EP - 908 PB - Elsevier CY - Amsterdam AN - OPUS4-26291 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -