TY - CONF A1 - Kalinka, Gerhard T1 - Bestimmung zeitabhängiger lokaler Eigenschaften von Polymeren mit der Nano-Indentationstechnik T2 - 15. Nationales SAMPE Symposium, BAM CY - Berlin, Germany DA - 2009-02-18 PY - 2009 AN - OPUS4-19013 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Local mechanical relaxation time spectroscopy with using the nano indentation technique T2 - THERMOSETS 2009 CY - Berlin, Germany DA - 2009-10-01 PY - 2009 AN - OPUS4-20123 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marotzke, Christian A1 - Kalinka, Gerhard T1 - Local failure processes in fiber reinforced polymers N2 - The breakage of a fiber and its effect on the strain energy is studied in a model composite, this is, a single fiber embedded in a dogbone specimen. The fracture process is recorded by an acoustic emission device, the crack patterns are monitored under a microscope. A finite element analysis is performed in order to estimate the energy released by different failure scenarios. The abilities and limitations of the acoustic emission analysis in characterizing different failure types in fiber reinforced composites are evaluated. T2 - ICCM17 - 17th International conference on composite materials CY - Edinburgh, UK DA - 2009-07-27 KW - Fiber KW - Interface KW - Composite material KW - Failure KW - Acoustic emission KW - Fracture mechanics KW - Energy release rate KW - Finite element analysis PY - 2009 IS - D7:8 SP - 1 EP - 10 CY - Edinburgh, UK AN - OPUS4-21295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Single Fiber Pull-out Test T2 - 4th International CFK-Valley Stade Convention CY - Stade, Germany DA - 2010-06-15 PY - 2010 AN - OPUS4-23289 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pommet, M. A1 - Juntaro, J. A1 - Heng, J.Y.Y. A1 - Mantalaris, A. A1 - Lee, A.F. A1 - Wilson, K. A1 - Kalinka, Gerhard A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Surface modification of natural fibers using bacteria: depositing bacterial cellulose onto natural fibers to create hierarchical fiber reinforced nanocomposites N2 - Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria (Acetobacter xylinum) to deposit nanosized bacterial cellulose around natural fibers, which enhances their adhesion to renewable polymers. This paper describes the process of modifying large quantities of natural fibers with bacterial cellulose through their use as substrates for bacteria during fermentation. The modified fibers were characterized by scanning electron microscopy, single fiber tensile tests, X-ray photoelectron spectroscopy, and inverse gas chromatography to determine their surface and mechanical properties. The practical adhesion between the modified fibers and the renewable polymers cellulose acetate butyrate and poly(l-lactic acid) was quantified using the single fiber pullout test. KW - Composires KW - Bacteria KW - Surface KW - Cellulose natural fibers PY - 2008 DO - https://doi.org/10.1021/bm800169g SN - 1525-7797 VL - 9 IS - 6 SP - 1643 EP - 1651 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juntaro, J. A1 - Pommet, M. A1 - Kalinka, Gerhard A1 - Mantalaris, A. A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Creating Hierarchical Structures in Renewable Composites by Attaching Bacterial Cellulose onto Sisal Fibers KW - Nanotubes KW - Cellulose KW - Polymer KW - Interface KW - Hierarchical Structures PY - 2008 DO - https://doi.org/10.1002/adma.200703176 SN - 0935-9648 SN - 1521-4095 VL - 20 IS - 16 SP - 3122 EP - 3126 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tran, M.Q. A1 - Ho, K.K.C. A1 - Kalinka, Gerhard A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Carbon fibre reinforced poly(vinylidene fluoride): Impact of matrix modification on fibre/polymer adhesion N2 - The quality of interfacial interaction is dictated by the surface chemistry of the carbon fibres and the composition of the matrix. The composition of poly(vinylidene fluoride) (PVDF) was modified by the addition of maleic anhydride grafted PVDF. The surface properties of the various matrix formulations were characterised by contact angle and electrokinetic measurements. Carbon fibres were modified by industrial electrochemical oxidation and oxidation in nitric acid, or the use of a traditional epoxy-sizing of industrially oxidised fibres. The surface composition, morphology and wetting behaviour of the carbon fibres was characterised. The interaction between modified PVDF and the carbon fibres was studied by direct contact angle measurements between PVDF melt on single carbon fibres and by single fibre pull-out tests. The best wetting and adhesion behaviour was achieved between PVDF containing 5 ppm grafted maleic anhydride (MAH) and epoxy-sized carbon fibres. The addition of MAH-grafted PVDF to the unmodified PVDF caused the apparent interfacial shear strength to increase by 184%. The apparent interfacial shear strength of this fibre–matrix combination allowed for the utilisation of 100% of the yield tensile strength of PVDF. KW - A. Carbon fibres KW - A. Coupling agents KW - B. Interface KW - B. Adhesion KW - Wetting PY - 2008 DO - https://doi.org/10.1016/j.compscitech.2008.02.021 SN - 0266-3538 VL - 68 IS - 7-8 SP - 1766 EP - 1776 PB - Elsevier CY - Barking AN - OPUS4-18259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Godara, A. A1 - Gorbatikh, L. A1 - Kalinka, Gerhard A1 - Warrier, A. A1 - Rochez, O. A1 - Mezzo, L. A1 - Luizi, F. A1 - van Vuure, A.W. A1 - Lomov, S.V. A1 - Verpoest, I. T1 - Interfacial shear strength of a glass fiber/epoxy bonding in composites modified with carbon nanotubes N2 - In recent years, carbon nanotubes (CNTs) grown on fibers have attracted a lot of interest as an additional reinforcing component in conventional fiber-reinforced composites to improve the properties of the fiber/matrix interface. Due to harsh growth conditions, the CNT-grafted fibers often exhibit degraded tensile properties. In the current study we explore an alternative approach to deliver CNTs to the fiber surface by dispersing CNTs in the fiber sizing formulation. This route takes advantage of the developed techniques for CNT dispersion in resins and introduces no damage to the fibers. We focus on unidirectional glass fiber/epoxy macro-composites where CNTs are introduced in three ways: (1) in the fiber sizing, (2) in the matrix and (3) in the fiber sizing and matrix simultaneously. Interfacial shear strength (IFSS) is investigated using single-fiber push-out microindentation. The results of the test reveal an increase of IFSS in all three cases. The maximum gain (over 90%) is achieved in the composite where CNTs are introduced solely in the fiber sizing. KW - A. Carbon nanotubes KW - A. Hybrid composites KW - A. Polymer-matrix composites (PMCs) KW - B. Interfacial strength PY - 2010 DO - https://doi.org/10.1016/j.compscitech.2010.04.010 SN - 0266-3538 VL - 70 IS - 9 SP - 1346 EP - 1352 PB - Elsevier CY - Barking AN - OPUS4-22171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Bestimmung der Haftfestigkeit in Verbundwerkstoffen mittels Indentations- und Durchdrückexperimenten T2 - DGM Fachausschuss "Gefüge und Eigenschaften von Polymerwerkstoffen" CY - Hamburg, Germany DA - 2004-11-26 PY - 2004 AN - OPUS4-4705 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Mikromechanische Testmethoden zur Bestimmung von Haftung und Reibung in Faserverbundwerkstoffen T2 - Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), Institut für Strukturmechanik CY - Braunschweig, Germany DA - 2004-02-04 PY - 2004 AN - OPUS4-4700 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Mechanische Charakterisierung des Faser-Matrix-Interface mit Einzelfaser-Tests T2 - Werkstoffwoche 2004: Kongress für innovative Werkstoffe, Verfahren und Anwendungen CY - Munich, Germany DA - 2004-09-21 PY - 2004 AN - OPUS4-4701 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - A model of spherulitic crystallization based on growing lameallae T2 - 9th Microsymposium of Electron Microscopy in Materials Science CY - Lutherstadt Wittenberg, Germany DA - 2004-05-06 PY - 2004 AN - OPUS4-4702 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Micro indentation near stiff-soft phase boundaries T2 - Polydays 2004 CY - Potsdam, Germany DA - 2004-10-04 PY - 2004 AN - OPUS4-4703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Micro indentation near stiff-soft boundaries T2 - "Nanomech5, 5th European Symposium on nano-Mechanical Testing" CY - Hückelhoven, Germany DA - 2004-09-07 PY - 2004 AN - OPUS4-4704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Charakterisierung des Interface-Versagens in Faserverbundwerkstoffen mit mikromechanischen Testmethoden T2 - 5. Berliner Polymeren Tage CY - Potsdam, Germany DA - 1994-10-05 PY - 1994 AN - OPUS4-5910 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Bestimmung der Interface-Festigkeit oder -Trennarbeit mit dem Pull-out-Versuch T2 - Verbundwerkstoffe und Werkstoffverbunde CY - Kassel, Germany DA - 2005-04-06 PY - 2005 AN - OPUS4-6084 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Bestimmung der Interface-Festigkeit in carbonfaserverstärkten Werkstoffen T2 - Verbundwerkstoffe und Werkstoffverbunde CY - Kassel, Germany DA - 06.04.2005 PY - 2005 AN - OPUS4-6085 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Micro indentation and scratch tests for surface characterisation T2 - XXII. Donauländergespräche über die natürliche und künstliche Alterung von Polymeren CY - Berlin, Germany DA - 2001-09-17 PY - 2001 AN - OPUS4-7506 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Munz, Martin A1 - Chung, Jae Un A1 - Kalinka, Gerhard ED - Possart, W. T1 - Mapping Epoxy Interphases T2 - 7th European Conference on Adhesion ; 7th EURADH CY - Freiberg, Germany DA - 2004-09-01 KW - Interface KW - Interphase KW - Epoxy KW - Copper (Cu) KW - Polyvinylpyrrolidone (PVP) KW - AFM/SFM KW - DSI KW - EDX/EDS KW - Stiffness KW - Modulus KW - Interdiffusion PY - 2005 SN - 3-527-31263-3 VL - 7 SP - 103 EP - 123 PB - Wiley-VCH CY - Weinheim AN - OPUS4-10894 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalinka, Gerhard T1 - Mikromechanik T2 - BAM, DGM Fachausschuss "Gefüge und Eigenschaften von Polymerwerkstoffen" CY - Berlin, Germany DA - 2003-12-05 PY - 2003 AN - OPUS4-4088 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hinrichs, V. A1 - Kalinka, Gerhard A1 - Hinrichsen, G. T1 - An Avrami-based model for the description of the secondary crystallization of polymers N2 - A mathematical model for the description of the overall crystallization of polymers has been developed which separates the pure geometric spreading of the semicrystalline superstructures from the increasing crystallinity inside these entities. The model uses the Avrami theory for the geometric part and a freely optional function for the increasing local crystallinity. The two functions are combined by a mathematical procedure called convolution. The free option of the local crystallinity function enables this model to permit calculation of this function, which is not accessible to direct measurement. Thus with given Avrami parameters and measured values of the time-dependent overall crystallinity, this function of the local crystallinity (secondary crystallization function) can be calculated. The model has been applied to test data produced by computer simulations. KW - Thermoplaste KW - Kristallisation KW - Nachkristallisation KW - Sphärolithe KW - Kristallisationskinetik KW - Modellrechnung PY - 1996 DO - https://doi.org/10.1080/00222349608220382 SN - 0022-2348 SN - 1525-609X VL - 35 IS - 3-4 SP - 295 EP - 302 PB - Dekker Chemistry CY - New York, NY AN - OPUS4-11983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schulz, Eckhard A1 - Kalinka, Gerhard A1 - Auersch, W. T1 - Effect of Transcrystallization in Carbon Fiber Reinforced Poly(p/phenylene sulfide) Composites on the Interfacial Shear Strength Investigated with the Single Fiber Pull-Out Test N2 - The effect of transcrystallinity in carbon fiber reinforced poly(p-phenylene sulfide (PPS) composites on the apparent shear strength was investigated with the single fiber pull-out test. Transcrystalline zones around the reinforcing fibers do not seem to improve the adhesion level significantly. Neighbor fibers hinder the formation of the transcrystalline zone and a ductile fracture behavior can be observed. However, the apparent strength level is slightly higher for composites containing such reinforcing neighbor fibers compared with single fiber composite samples. During annealing a brittle interface can be formed in the multifiber composite yielding a higher level of the apparent shear strength. KW - Thermoplaste KW - Kristallisation KW - Transkristallisation KW - Interface KW - Verbundwerkstoffe KW - Pull-out KW - Haftung KW - Adhäsion KW - Reibung PY - 1996 DO - https://doi.org/10.1080/00222349608220393 SN - 0022-2348 SN - 1525-609X VL - 35 IS - 3-4 SP - 527 EP - 546 PB - Dekker Chemistry CY - New York, NY AN - OPUS4-11987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -