126
Global Atmospheric Evolution: Impact of Anthropogenic Activities
1 INTRODUCTION
The substantial development of plastic materials in modem technology induced us
to consider their behaviour in the many circumstances that make use of
temperature raising:
• The production of manufactured objects necessarily uses glues,
varnishes, paints which are polymers. Manufacturing processes use
heating, therefore polymers are also heated (a varnish laid on metallic
packaging is subjected to the temperature necessary to its formation).
• Conflagration is a risk that has to be known in order to be fought. Thus
knowledge of the participation of plastic materials in the spread of fire
and in the emission of gases and fumes is essential.
• Destruction has to be anticipated, because an important part of
industrial, domestic, and hospital wastes is composed of plastic materials.
Most often, these wastes are incinerated, but they can also be treated in
order to constitute raw materials for other industrial activities.
Thus, before manufacture, incineration or recycling, the best heating conditions
have to be determined, and the risks for the environment due to the release of
gases formed have to be known.
Many authors were interested by this problem. We can mention some: Renman et
al [I] determined isocyanate and aromatic amine emissions from thermally
degraded polyurethanes. Chaigneau et al studied pyrolysis of polyurethanes [2]
and polyvinyl chloride [3] between 500°C and 800°C and characterized the toxic
gases emitted. Barabas et al [4] studied the volatile products of polypropylene
thermal oxidation.
The aim of our study is the analysis of some toxic gases (carbon oxides, carbonyl
compounds and other hydrocarbons, hydrogen cyanide, isocyanates, hydrogen
chloride) emitted during the thermal analysis of various samples of plastics: an
acrylic varnish, a polypropylene film, a polyurethane adhesive, a polyvinyl
chloride bottle.
2
MATERIALS AND METHODS
2.1 Samples
Four samples were studied:
• the acrylic varnish was liquid and white. It was composed of:
n Butyl Methacrylate (24%)
Ethylcellulose (3%)
Saccharose acetobutyrate (0,8%)
Polyethylene (1 %)
Methyl Ethyl Ketone (71,2%)
For the thermal analyses in the laboratory, it was necessary to spread it
in a thin coat over a glass slab. After solvent evaporation in a drying
oven at 40°C, the varnish film was removed. An approximately 30 mg
sample was used for each test.
Global Atmospheric Evolution: Impact of Anthropogenic Activities
1 INTRODUCTION
The substantial development of plastic materials in modem technology induced us
to consider their behaviour in the many circumstances that make use of
temperature raising:
• The production of manufactured objects necessarily uses glues,
varnishes, paints which are polymers. Manufacturing processes use
heating, therefore polymers are also heated (a varnish laid on metallic
packaging is subjected to the temperature necessary to its formation).
• Conflagration is a risk that has to be known in order to be fought. Thus
knowledge of the participation of plastic materials in the spread of fire
and in the emission of gases and fumes is essential.
• Destruction has to be anticipated, because an important part of
industrial, domestic, and hospital wastes is composed of plastic materials.
Most often, these wastes are incinerated, but they can also be treated in
order to constitute raw materials for other industrial activities.
Thus, before manufacture, incineration or recycling, the best heating conditions
have to be determined, and the risks for the environment due to the release of
gases formed have to be known.
Many authors were interested by this problem. We can mention some: Renman et
al [I] determined isocyanate and aromatic amine emissions from thermally
degraded polyurethanes. Chaigneau et al studied pyrolysis of polyurethanes [2]
and polyvinyl chloride [3] between 500°C and 800°C and characterized the toxic
gases emitted. Barabas et al [4] studied the volatile products of polypropylene
thermal oxidation.
The aim of our study is the analysis of some toxic gases (carbon oxides, carbonyl
compounds and other hydrocarbons, hydrogen cyanide, isocyanates, hydrogen
chloride) emitted during the thermal analysis of various samples of plastics: an
acrylic varnish, a polypropylene film, a polyurethane adhesive, a polyvinyl
chloride bottle.
2
MATERIALS AND METHODS
2.1 Samples
Four samples were studied:
• the acrylic varnish was liquid and white. It was composed of:
n Butyl Methacrylate (24%)
Ethylcellulose (3%)
Saccharose acetobutyrate (0,8%)
Polyethylene (1 %)
Methyl Ethyl Ketone (71,2%)
For the thermal analyses in the laboratory, it was necessary to spread it
in a thin coat over a glass slab. After solvent evaporation in a drying
oven at 40°C, the varnish film was removed. An approximately 30 mg
sample was used for each test.