Heat release rate polypropylene nanocomposites

FIGURE 33.2. A plot of heat release rate (HRR) for pure polypropylene compared with a 4% loaded polypropylene/ clay nanocomposite. 

In the present study the combustibility of polypropylene nanocomposite was evaluated by a cone calorimeter. The tests were performed at an incident heat flux of 35 kW/m using the cone heater [21]. Peak heat release rate (RHR), mass loss rate (MLR), specific extinction area (SEA) data, earbon monoxide and heat of eombustion data measured at 35 kW/m2, are presented in Figs. 11 and 12. 

Polymer/fullerene [Ceol nanocomposites can be considered environmentally friendly alternatives to some traditional flame retardants. The presence of Ceo can markedly delay thermal oxidative degradation and reduce the flammability of polypropylene at very low loadings. It can decrease the heat release rate of polymeric materials by trapping the free radicals created through thermal degradation and combustion, and subsequently forming three-dimensional gelled networks. This network can increase the melt viscosity and consequently slow down combustion. Furthermore, the incorporation of Qo does not affect the physical properties of the polymer. 

The data for nanocomposites polymer/organoclay on the basis of polyamide-6 (PA-6), polyamide-12 (PA-12), polystyrene (PS) and polypropylene (PP), which are listed in table 11.1, were used for the relationships structure-flame-resistance characteristics. The maximum rate of heat release measured with the use of a cone calorimeter according to the standards ASTM 1354-92 and ISO/DIS 13927 [2], the values of which are also listed in Table 11.1, was used as flame-resistance characteristic of the indicated nanomaterials. 

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