Pyrolysis of polymers in the presence of a commercial clay

The catalytic effect of a commercial sepiolite in the pyrolysis of PE, PP, PS and EVA has been studied. The results obtained show that, despite the low “nominal” catalytic activity of this clay, it has enough catalytic properties to produce a marked decrease of the temperature of decomposition of PE and PP. However, the steric effects related to the substituents of PS and EVA cancels this catalytic behaviour. Experiments performed in an oxidizing atmosphere showed that the process is much more complex and involves more decomposition steps, but no noticeable decrease in the temperature of any process may be related to the presence of the clay. Nonetheless, the yield of carbonous residue is higher in the presence of the sepiolite.