posted on 2018-07-02, 10:41authored byJirachai Mingbunjerdsuk
This research is concerned with the characterisation and properties of natural
rubber (NR), styrene-butadiene rubber (SBR) and acrylonitrile-butadiene rubber
(NBR) nanocomposites. The fillers used were unmodified sodium
montmorillonite clay, three organically-modified clays with different types and
concentrations of modifiers, and, for comparison, a carbon black. The clays were
characterized by Fourier-transform infrared spectroscopy (FTIR),
thermogravimetric analysis (TGA) and x-ray diffraction (XRD). The composites
were prepared via melt compounding and sulphur curing in an internal mixer.
Better dispersion was found for the organoclays rather than for the unmodified
clay as was seen by scanning electron microscopy (SEM). Intercalation and some
exfoliation of certain organoclays in rubbers were achieved as revealed by XRD
and transmission electron microscopy (TEM). The most polar rubber proved more
effective in nanocomposite formation. The incorporation of organoclays affected
torque and curing time as measured using a Monsanto rheometer. The organoclays
can accelerate the vulcanization process, but the effect was reduced with
increasing clay loading. The crosslink density decreased with increasing
organoclay content. The static and dynamic mechanical properties of the rubber-layered
silicate composites such as tensile properties, modulus, tear strength,
fatigue life and dynamic visco-elastic properties are discussed. There was a
significant improvement in modulus, tensile strength and elongation at break as
compared to the composites prepared with the untreated clay. Dynamic
mechanical analysis shows an increase in the storage and loss modulus for the
nanocomposites. Overall, the content of clay and the type of modifier both affect
the curing and mechanical properties. Rubber-organoclay nanocomposites show a
good reinforcing effect which is comparable to that achieved with carbon black. In
particular, the tear and fatigue properties of the organoclay-rubber
nanocomposites exceeded those of the rubbers reinforced with carbon black.
Funding
Thailand, Government.
History
School
Aeronautical, Automotive, Chemical and Materials Engineering
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/
Publication date
2005
Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy at Loughborough University.