Kaolin-Epoxy-Based Nanocomposites: A Complementary Study of the Epoxy Curing by FTIR and Fluorescence Articles uri icon

publication date

  • May 2010

start page

  • 781

end page

  • 791

issue

  • 5

volume

  • 31

International Standard Serial Number (ISSN)

  • 0272-8397

Electronic International Standard Serial Number (EISSN)

  • 1548-0569

abstract

  • This work is focused on the study of the effect exerted by the presence of kaolin on the cure reaction of an epoxy-based polymer, discussing the influence of different kaolin
    pretreatments. During the last few years, the interest on polymer matrix
    nanocomposite materials has sharply increased because generally they
    show improved properties when compared with those of the neat polymer
    (without filler). Among this sort of materials, polymer clay
    nanocomposites have been widely studied. However, there are not many
    works about kaolin-based composites. Although several techniques have
    been used to monitor the cure process in epoxy-based composites such as
    Fourier transform. infrared spectroscopy (FTIR) or differential scanning
    calorimetry, only the use of the fluorescent response from a
    fluorophore seems to be adequate to monitor the reaction exactly at the
    interfaces at a molecular scale. In this work, FTIR and fluorimetry were
    used to monitor the cure reaction of the different composite systems at
    different curing temperatures. The analysis of FTIR experiments
    revealed that the presence of the reinforcement clay affects the extent
    of the cure reaction depending on the nature of its surface. On the
    other hand, the use of a fluorescent molecule chemically bonded to the
    reinforcement allows studying the curing exactly at the interface.
    Finally, with the collected data, a kinetic analysis was done and the
    results obtained were compared in terms of the technique used and the
    information source (interface or bulk). At the interface, the activation
    energy for the epoxy reaction is lower than that carried out in the
    bulk indicating that the reaction at the interface proceeds via a
    particular mechanism for which the reaction is favored. It seems that a
    higher amount of hydroxyl groups is capable of catalyzing the cure
    reaction.