27 research outputs found
Exfoliated graphite nanoplatelet-filled impact modified polypropylene nanocomposites: influence of particle diameter, filler loading, and coupling agent on the mechanical properties
Exfoliated graphite nanoplatelets (xGnP)-filled impact-modified
polypropylene (IMPP) composites were prepared at 2, 4, 6, and 8 wt \%
xGnP with and without the addition of a coupling agent and manufactured
using melt mixing followed by injection molding. The coupling agent used
in this study was polypropylene-graft-maleic anhydride (PP-g-MA). The
nanoparticles used were xGnP with three different sizes: xGnP(5) has an
average thickness of 10 nm, and an average platelet diameter of 5 mu m,
whereas xGnP(15) and xGnP(25) have the same thickness but average
diameters are 15 and 25 mu m, respectively. Test results show that
nanocomposites with smaller xGnP diameter exhibited better flexural and
tensile properties for both neat and compatibilized composites. For
composites containing a coupling agent, tensile and flexural modulus and
strength increased with the addition of xGnP. In the case of neat
composites, both tensile and flexural modulus and strength decreased at
higher filler loading levels. Increasing xGnP loading resulted in
reduction of elongation at break for both neat and composites containing
coupling agent. Explanation of this brittle behavior in a
nanoplatelet-filled IMPP is presented using scanning electron microscopy
and transmission electron microscopy
Detection of different oxidation states of individual manganese porphyrins during their reaction with oxygen at a solid/liquid interface
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