Gases emitted during thermal decomposition of a polypropylene film and a polyurethane adhesive

The thermal decomposition of a polypropylene film, a polyurethane adhesive, as well as a polypropylene coated with a polyurethane adhesive have been studied by a thermogravimetric (TG) analysis, at a heating rate of 5°C a minute with air flow. During the thermal analysis different decomposition steps which correspond to different weight loss rates were obtained on thermal curves. Gases were collected between the different decomposition steps and then analyzed. The results reported deal with the conversion of carbon into oxides and aldehydes—ketones, and also with that of nitrogen into hydrogen cyanide and isocyanates. The findings lead to a better understanding of the hazards and risks of toxic emissions that may be generated by the gas formation following heating of these materials.