Studies on the Mechanism by Which the Formation of Nanocomposites Enhances Thermal Stability

Abstract

Polystyrene-clay and polystyrene-graphite nanocomposites have been prepared and used to explore the process by which the presence of clay or graphite in a nanocomposite enhances the thermal stability of polymers. This study has been designed to determine if the presence of paramagnetic iron in the matrix can result in radical trapping and thus enhance thermal stability. Nanocomposites were prepared by bulk polymerization using both iron-containing and iron-depleted clays and graphites, and they were characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, and cone calorimetry. The presence of structural iron, rather than that present as an impurity, significantly increases the onset temperature of thermal degradation in polymer-clay nanocomposites. Intercalated nanocomposites show an iron effect, but this is less important for exfoliated systems. Polymer-graphite nanocomposites show no difference between iron-free and iron-containing nanocomposites, presumably because the iron is not nanodispersed in the graphite.

A review on the role of interface in mechanical, thermal, and electrical properties of polymer composites

“…Second, they can create a network which can protect the polymer from degradation [229][230][231][232]. Third, they can act as radical traps [233]; and lastly, they are capable of altering the microstructure of the product [4,222]. Moreover, strong adhesion between the filler and matrix causes lower mobility of polymer chains followed by reduction of decomposition rate [234,235].…”

Synthesis, thermal and structural characterization of nanocomposites for potential applications in construction

“…Polymer-clay nanocomposite materials are reported to promote thermal [48,49], mechanical [50], molecular barriers [51], flame retardant behavior [52][53][54][55][56][57][58][59] and corrosion protection properties [60][61][62]. Therefore, the systematic investigation of the reaction possibility of PAA with synthetic C-S-H at low Ca/Si ratio (0.7) as well as to characterize the composite materials by nanotechnological methods are the main interests of this contribution.…”

The role of the trivalent metal in an LDH: Synthesis, characterization and fire properties of thermally stable PMMA/LDH systems

“…Recently, Jiao et al [4] reported that EVA/(Mg/Al/Fe-CO3) composites containing a variable amount of Fe 3+ ion obtained a V-0 rating in the UL-94 protocol, while with EVA/MgAl-CO3,(an iron-free hydrotalcite), dripping occurred. The presence of iron as a substitutional impurity in MMT has been shown to lead to radical trapping reactions and a reduction in the PHRR at low amounts of clay [23]. Kong et al have recently reported on a synthetic iron-containing MMT analog and found that the iron has a significant effect on the degradation and fire properties [24].…”