Poly(vinyl chloride)/metallic oxides/organically modified montmorillonite nanocomposites: Fire and smoke behavior

Abstract

Nanocomposites of poly(vinyl chloride), metallic oxides (copper, molybdenum, and zinc), and organically modified montmorillonite (O-MMT) were prepared in a melt-blending or intercalation-in-the-molten state process, and their morphology was assessed with X-ray diffraction and transmission electron microscopy. The formation of an intercalated/partially exfoliated hybrid microstructure was confirmed in every situation studied. The combustion and smoke emission properties were studied with cone calorimetry, limiting oxygen index, and thermogravimetry (TG) coupled with mass spectroscopy (MS). The results reveal that the metallic oxides had a significant effect on both the combustion properties and smoke suppression, whereas O-MMT only affected these properties discretely. Little interaction was observed in the joint use of these additives. The results also confirm the anticipation of dehydrochlorination, reductive coupling, and benzene suppression mechanisms resulting from the presence of copper, molybdenum, and zinc metals; these were indicated by the increase in carbonaceous char residue and the significant reduction in benzene formation, in this case indicated in the TG/MS measurements obtained.

Synthesis of copper(II)‐zinc‐molybdenum compounds as smoke suppressants for PVC compositions

“…The presence of copper (II) in the smoke suppressor composition apparently does not have significant synergistic effects, since SF‐4‐2 composition did not show better results than zinc composition SF‐1‐2, but too intense greenish coloration, as it can be seen in Figure 6 and Table 5. Some greenish coloration was expected due to the presence of copper (II) in SF‐4 and SF‐5, but the authors were looking for synergistic effects observed previously in other publications 5,6 . In the future, copper (I) compounds should be tested because, despite less stable than copper (II) compounds, they have the potential to impart a less negative effect on color.…”

PVC/MMT nanocomposites

“…Poly(vinyl chloride) (PVC) nanocomposites with layered silicates, especially montmorillonite, have gained increased attention in recent years due to reinforcement effects induced by inorganic filler. Improved thermal resistance, enhanced stiffness and barrier properties, as well as flame retardation have been reported [1][2][3][4][5][6].…”

Effect of phytic acid–modified layered double hydroxide on flammability and mechanical properties of intumescent flame retardant polypropylene system

“…The A similar trend was also found in the THR results, as shown in The emission of smoke is regarded as another important parameter in the halogen-free flame retardant polymer composites. 25 The total smoke production versus time curve is presented in Figure 6. It can be observed that the smoke emission of PP composites during the combustion process is significantly decreased compared with that of neat PP, demonstrating the smoke suppression effect of the nano-fillers.…”