Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM

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  • Publication
    Formation of new thermosets by the reaction of cyanates with thiophenols
    ( 2008)
    Bauer, M.
    ;
    Bauer, J.
    Sulfur-containing aromatic thermosets, mainly consisting of aryloxy- and arylthio-substituted 1,3,5-triazines, have been prepared through the reaction of difunctional cyanates with mono- and difunctional aromatic thiols. A straightforward three-step reaction scheme is proposed and verified by the identification of key substances: (1) the addition of thiol and cyanate groups, (2) the stepwise addition of (thio)imino carbonic esters with one another, and (3) the ring closure of chain-extended (thio)imino carbonic esters to form 1,3,5-triazines. Reactions of types 2 and 3 are associated with an abstraction of phenol or thiophenol, which can enter into reaction 1 again. Characterization Of the curing behavior of dicyanate of bisphenol A with thiophenol as well as dimercaptodiphenyl sulfide by differential scanning calorimetry shows that the reaction rates are significantly enhanced by the admixture of thiols to the cyanate. Dynamic mechanical analysis of resulting thermosets showed that large amounts of comonomers can be incorporated into the network resulting in a decrease of glass temperature but increase of fracture toughness. Finally, the fully cured thermosets resulting front the reaction of dicyanate of bisphenol A with different admixtures of dimercaptodiphenyl sulfide were characterized by cone calorimetry to get information about flame retardancy. The flame retardancy is influenced by incorporation of dimercaptodiphenyl sulfide into the triazine network only slightly. .
  • Publication
    Evaluation of chiral dopants for LCD applications
    ( 2006)
    Bauer, M.
    ;
    Boeffel, C.
    ;
    Kuschel, F.
    ;
    Zaschke, H.
    A large number of new synthesized as well as known chiral dopants with respect to their helical twisting power (HTP), the phase stability of cholesteric solution prepared by doping nematic LC mixtures, the host dependence of the chiral induction, and the photostability has been examined. The evaluation led to the result that only few compounds fulfill the stringent application requirements of LCD manufacturing, especially with reference to bistable cholesteric devices.
  • Publication
    Lightweight construction: Sandwiches with nap cores
    ( 2006)
    Bauer, M.
    ;
    Friede, P.
    ;
    Uhlig, C.
  • Publication
    Sandwiches mit Noppenwabenkern
    ( 2006)
    Bauer, M.
    ;
    Friede, P.
    ;
    Uhlig, C.
    Großflächige Strukturen mit geringem Gewicht lassen sich durch das Prinzip der Sandwichbauweise vielfältig realisieren. Aus wirtschaftlicher Sicht versprechen Noppenwabenkerne vielfältige Vorteile. Sie sind flexibel herstellbar und erschließen neue Einsatzgebiete in Automobil-, Flugzeug- und Bootsbau.
  • Publication
    Dendrimers based on [1,3,5]-triazines
    ( 2006)
    Steffensen, M.B.
    ;
    Hollink, E.
    ;
    Kuschel, F.
    ;
    Bauer, M.
    ;
    Simanek, E.E.
    A comprehensive and chronological account of dendrimers based on [1,3,5]-triazines is provided. Synthetic strategies to install the triazine through cycloaddition, cyclotrimerization, and nucleophilic aromatic substitution of cyanuric chloride are discussed. Motivations and applications of these architectures are surveyed, including the preparation of supramolecular assemblies in the solution and solid states and their use in medicines, advanced materials, and separations when anchored to solid supports.
  • Publication
    Super compact optical add-drop multiplexer for FTTH applications based on low-loss polymer waveguide materials
    ( 2005)
    Keil, N.
    ;
    Yao, H.H.
    ;
    Zawadzki, C.
    ;
    Beyer, F.
    ;
    Radmer, O.
    ;
    Bauer, M.
    ;
    Dreyer, C.
    Four- and eight-channel arrayed-waveguide grating (AWG) and fixed optical add-drop multiplexer (OADM) devices with channel spacing of 1200 and 600 GHz have been fabricated using super-high refractive index contrast (Delta n=0.020) triazine containing polymers. Accordingly, the size of the four-channel AWG was only 10x3 mm and the insertion loss was 3 dB.
  • Publication
    Polymere Anwendungen in der integrierten Optik - ein Überblick mit ausgewählten Beispielen
    ( 2003)
    Dreyer, C.
    ;
    Schneider, J.
    ;
    Göcks, K.
    ;
    Beuster, B.
    ;
    Bauer, M.
    ;
    Keil, N.
    ;
    Yao, H.
    ;
    Zawadzki, C.
    ;
    Radmer, O.
    Im Rahmen dieser Veröffentlichung werden Arbeiten zur Entwicklung von Spezialpolymeren für die integrierte Optik am Beispiel ausgewählter optischer Bauelemente (thermooptische Schalter undArrayed Waveguide Gratings) dargestellt, insbesondere für die Langstreckendatenübertragung im Wellenlängenbereich um 1.55 µm. Es wurden fluorierte Polyacrylate, Polycyanurate und triazinhaltige Reaktivpolymere untersucht.
  • Publication
    New reactive polymeric systems for use as waveguide materials in integrated optics
    ( 2003)
    Dreyer, C.
    ;
    Schneider, J.
    ;
    Göcks, K.
    ;
    Beuster, B.
    ;
    Bauer, M.
    ;
    Keil, N.
    ;
    Yao, H.
    ;
    Zawadzki, C.
    Cross-linked polymeric materials are used in a wide range of applications. Special compositions are used in micro-system technologies and its utilization is extending to integrated optics. We have been working for several years in the field of polymers for optical applications. Highly fluorinated polycyanurate systems have been proven as promising waveguide materials in integrated optics. The refractive index can be adjusted reproducibly in a wide range almost continuously. The layer quality was optimized. Low optical losses of less than 0.3 dB/cm@1550nm were obtained and working optical prototypes were developed. The birefringence had been a major problem, but this was solved by adjusting the coefficient of thermal expansion of substrate and film. We will report in this paper on the polycyanurate ester resins and the new triazine containing polymeric systems.
  • Publication
    Polymere für Anwendungen in der optischen Nachrichtentechnik - eine Möglichkeit zur Steigerung der Effizienz des Internet
    ( 2002)
    Dreyer, C.
    ;
    Bauer, M.
    ;
    Schneider, J.
    ;
    Bauer, J.
    ;
    Keil, N.
    ;
    Yao, H.
    ;
    Zawadzki, C.