The oxidative pyrolysis of plastics

Experiments using a thermobalance, a hot‐plate and a moving furnace have all shown that polymers can evolve oxidation products in air even at moderate temperatures. These gases can include carbon monoxide, formaldehyde and acrolein. The amounts are generally low except near the very top of the temperature range used in some processes. Tests in the vicinity of three different extruders have confirmed some of these small‐scale findings but also showed that the evolved gases were adequately handled by the ventilation installed. The evolution of other gases in certain cases has also been briefly studied. Some measure of the heat evolved in oxidative pyrolysis has also been obtained for polyethylene. The polymers investigated were low density and high density polyethylene, poly(ethylene vinylacetate), polypropylene, poly(vinylonitrille) polypropylene, poly(vinylchloride), polystyrene, poly(methylmethacrylate), polycarbonate, poly(ethylene terephthalate), nylon 6‐6, acrylonitrile/butadiene/styrene and one nature material (wood).