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- Cone calorimeter (1)
- Fire retardancy (1)
- Montmorillonites (1)
- Nanocomposites (1)
- PVC (1)
- Polypropylene-graft-maleic anhydride (1)
- TG-FTIR (1)
- Thermal stability (1)
- X-ray (1)
- ZnS (1)
The morphology and thermal behaviour of polypropylenegraftmaleic anhydride (PPgMA) layered silicate (montmorillonite) nanocomposites were investigated using X-ray diffraction, transmission electron microscopy, differential scanning calorimetry and thermogravimetry. The study focuses on the influence of the presence of oxygen during the preparation of PPgMAnanocomposite using two different modified clays. The nanocomposites show tactoid, intercalated and exfoliated structures side by side with different dominant states depending on the clay used and on the processing conditions. The systems are described as multi-component blends rather than binary blends since the organic ions do not only change the mixing behaviour, but also influence material properties. Beside the physical barrier property of the clay layers also chemical processes were found to play an important role.
The flame retardant effect of zinc sulphide (ZnS) in plasticised poly(vinyl chloride) (PVC-P) materials was investigated. PVC-P containing different combinations of additives such as 5% ZnS, 5% of antimony oxide (Sb2O3) and 5% of mixtures based on Sb2O3 and ZnS were compared. The thermal degradation and the combustion behaviour were studied using thermogravimetry (TG), coupled with FTIR (TG-FTIR) or with mass spectroscopy (TG-MS), and a cone calorimeter, respectively. A detailed and unambiguous understanding of the decomposition and release of the pyrolysis products was obtained using both TG-MS and TG-FTIR. The influence of ZnS, Sb2O3 and the corresponding mixtures on the thermal decomposition of PVC-P was demonstrated. Synergism was observed for the combination of the two additives. The combustion behaviour (time to ignition, heat release, smoke production, mass loss, CO production) was monitored versus external heat fluxes between 30 and 75 kW m-2 with the cone calorimeter. Adding 5% of ZnS has no significant influence on the fire behaviour of PVC-P materials beyond a dilution effect, whereas Sb2O3 works as an effective fire retardant. Synergism of ZnS and Sb2O3 allows the possibility of replacing half of Sb2O3 by ZnS to reach equivalent fire retardancy.