C. Arfi et at. : Gaseous Toxic Emission from Plastic Materials
127
• the polypropylene film was meant to cover a metallic packaging. It was
transparent.
the polyurethane adhesive was meant to paste the polypropylene film on
the packaging. It was delivered as a semi rigid block with small cavities.
• the polyvinyl chloride came from bottles of mineral water. It was rigid,
transparent and lightly tinted.
2.2 Thermal analyses
The thermal behaviour of these samples was studied in a TG-DTA SETARAM
apparatus, with a platinum crucible and a platinum rhodium thermocouple. It was
possible to study simultaneously weight loss of the sample (TG) as a function of
temperature and to observe exothermal and endothermal phenomena (DTA).
(Fig. O.
The experimental conditions were a heating rate of 5°C/mn to a maximum
temperature of 650°C. An air flow drew the emitted gases towards impingers at an
average rate of 10 ml a minute. We associated those techniques (TG-DTA) with
those of analytical chemistry to analyze the gases emitted during the thermal
decomposition within the temperatures ranges corresponding to different
decomposition rates.
2.3 Gas sampling
Gases emitted inside the apparatus were led to an evacuation fitted with a three way
valve. This made it possible to selectively feed the gas emission into one of the
three impingers through a "Pulse pomp environment INC" pump.
The selection differed according to the nature of the collected gas.
•
•
•
•
•
For acid gases (C02, HCN, HCl) the collection flasks contained a sodium
hydroxide solution without carbonate in which was placed a glass
bubbler [5].
Carbonyl compounds were collected on silica cartridges (Sep-Pack CI8)
coated with 2-4 dinitrophenyl hydrazine in acetonitrile [6].
Isocyanates were collected in impingers charged with 1-(2methoxyphenyl) piperazine in acetonitrile [6].
Other hydrocarbons were collected in flasks containing ethyl acetate.
For carbon monoxide assays, gas was collected in a teflon collection bag
equipped with a valve [6].
2.4 Gas determination methods
• Carbon dioxide fixed as sodium carbonate, as well as hydrogen chloride
fixed as sodium chloride were assayed by a potentiometric method in
the presence of excess sodium hydroxide.
127
• the polypropylene film was meant to cover a metallic packaging. It was
transparent.
the polyurethane adhesive was meant to paste the polypropylene film on
the packaging. It was delivered as a semi rigid block with small cavities.
• the polyvinyl chloride came from bottles of mineral water. It was rigid,
transparent and lightly tinted.
2.2 Thermal analyses
The thermal behaviour of these samples was studied in a TG-DTA SETARAM
apparatus, with a platinum crucible and a platinum rhodium thermocouple. It was
possible to study simultaneously weight loss of the sample (TG) as a function of
temperature and to observe exothermal and endothermal phenomena (DTA).
(Fig. O.
The experimental conditions were a heating rate of 5°C/mn to a maximum
temperature of 650°C. An air flow drew the emitted gases towards impingers at an
average rate of 10 ml a minute. We associated those techniques (TG-DTA) with
those of analytical chemistry to analyze the gases emitted during the thermal
decomposition within the temperatures ranges corresponding to different
decomposition rates.
2.3 Gas sampling
Gases emitted inside the apparatus were led to an evacuation fitted with a three way
valve. This made it possible to selectively feed the gas emission into one of the
three impingers through a "Pulse pomp environment INC" pump.
The selection differed according to the nature of the collected gas.
•
•
•
•
•
For acid gases (C02, HCN, HCl) the collection flasks contained a sodium
hydroxide solution without carbonate in which was placed a glass
bubbler [5].
Carbonyl compounds were collected on silica cartridges (Sep-Pack CI8)
coated with 2-4 dinitrophenyl hydrazine in acetonitrile [6].
Isocyanates were collected in impingers charged with 1-(2methoxyphenyl) piperazine in acetonitrile [6].
Other hydrocarbons were collected in flasks containing ethyl acetate.
For carbon monoxide assays, gas was collected in a teflon collection bag
equipped with a valve [6].
2.4 Gas determination methods
• Carbon dioxide fixed as sodium carbonate, as well as hydrogen chloride
fixed as sodium chloride were assayed by a potentiometric method in
the presence of excess sodium hydroxide.