## 3 Results and Discussion
### Analysis of Thermal Decomposition Products (Pyrolysis and GC-MS)  
The Py-GCMS showed different results for the included plastics, which are described in the next paragraphs. In performing pyrolysis, the heating of the polymers revealed which substances were produced in abundance and in trace amounts as a result of the process.  
Acrylonitrile-butadiene-styrene copolymer (ABS). The same spectrum of pollutants was obtained at both temperatures, although the intensities of most pollutants were higher at 250 \({}^{\circ}\)C than at 200 \({}^{\circ}\)C. The complete table of degradation products for the temperature 200 \({}^{\circ}\)C (Table S1) and 250 \({}^{\circ}\)C (Table S2) can be found in the Supporting Information. Styrene was the main component detected in the vapor space under these conditions. Furthermore, benzaldehyde, acrolein, n-alkanals (acetaldehyde to n-nonanal), acetophenone, 2-phenylisopropanol, methylstyrene, ethylbenzene, toluene, cumene, 2-methyl-1-propene, and a mixture of other unsaturated aliphatic hydrocarbons (highest single concentration: 1-tridecene) were detected. In low concentrations, there was evidence of acrylonitrile, 4-vinylcyclohexene, and acetone, as well as traces of benzene, ethanol, furan, tert-butanol, 2-butanone, propanentifile, phenol, and other alkalanals and alkyl aromatics.  
Low-density polyethylene (LDPE). Under these conditions (Tables S3 and S4), acetaldehyde was detected as the main component in the vapor space, and at 200 \({}^{\circ}\)C, acetic acid and formic acid were also detected. Furthermore, n-butane, 2-butanone, and n-alkanals (n-propanal to n-nonanal) were also detected. In low concentrations, there were indications of ethanol, acrolein, acetone, propane, further n-alkanes (n-pentane to n-dodecane), as well as traces of methanol, n-propanol, n-butanol 2-and 3-alkanones and, at 200 \({}^{\circ}\)C, dihydro-2(3H)-furanone (butylrolactone).  
Polypropylene (PP). The main components detected under these conditions in the vapor space were acetone and, at 200 \({}^{\circ}\)C (Table S5), acetic acid and formic acid. The latter could not be detected at 250 \({}^{\circ}\)C (Table S6) and acetic acid was detected only in low concentrations. With the exception of some ketones, the concentrations of the other contaminants were higher at 250 \({}^{\circ}\)C. A complex mixture of saturated and unsaturated aldehydes (highest concentrations: metharcolein, acetaldehyde), saturated and unsaturated hydrocarbons (highest concentrations: 2,4-dimethyl-1-heptene, 2-methyl-1-pentene, 2-methyl-1-propene, n-pentane), saturated and unsaturated ketones (highest concentrations: 2,4-pentanedione, 2-pentanone, 4-methyl-2-heptanone, methyl Isobutyl ketone), and alcohols (highest concentrations: methanol and higher branched alcohols that could not be clearly identified) were detected.  
be detected in trace amounts at 200 \({}^{\circ}\)C). At 250 \({}^{\circ}\)C, there was also evidence of further furan compounds, ketones, and formaldehyde derivatives, which could not be clearly identified.  
Polystyrene (PS). A similar spectrum of pollutants was obtained at both temperatures (Tables S11 and S12), although the concentrations of most pollutants were higher at 250 \({}^{\circ}\)C than at 200 \({}^{\circ}\)C. The main components determined in the vapor space under these conditions were styrene and benzaldehyde. Furthermore, acetophenone, 2-phenylpropenal, ethylbenzene, methylstyrene, cumene, propylbenzene, phenol, phenylacetaldehyde and phenyloxirane were detected. Benzene, formaldehyde, acetic acid, acetaldehyde, benzyl alcohol and a propyl toluene were identified in low concentrations at 250 \({}^{\circ}\)C, which could only be detected in the trace range at 200 \({}^{\circ}\)C or not at all in the case of acetic acid. In the trace range, there were also indications of n-alkanals, 2-alkanones, benzyl methyl ketone, unsaturated ketones, other aromatic hydrocarbons, and alcohols, in particular at 250 \({}^{\circ}\)C.