Secondary reactions in the analysis of microplastics by analytical pyrolysis

Mixtures of plastic particles different types were analysed by Py-GC-MS in order to investigate the effect polymer interactions on composition pyrolysates. Pyrolysis products associated secondary reactions observed when poly(ethylene terephthalate) (PET) pyrolysed presence poly(vinylchloride) (PVC) and polyamides PA6 (polycaproamide) PA66 (poly(hexamethylene adipamide)). Co-pyrolysis PET PVC produced mono dichloroethyl esters terephthalic acid due addition HCl double bond vinyl group. Benzyl chloride, benzoyl 4-chlorobenzoic also tentatively identified. The interaction between above all brought about formation aromatic nitriles including methyl ethyl benzonitrile, 1,4-benzenedicarbonitrile, 4-cyanoethyl benzoate, 4-cyano benzoic acid. In addition, co-pyrolysis N-alkyl amides generated benzene diphenyl, while N-hexylbenzamide was from pyrolysis with hexyl-1-amine or hexan-1,6-diamine. PE (polyethylene), PP (polypropylene), PS (polystyrene) did not exhibit significant interactions. Calibration curves built up single 10–120 µg range used quantify each mixture using typical pyrolytic markers. highest deviations recovery lowest RSD for PA6, polyolefins satisfactory RSD. detection can be as markers co-presence polymers supporting their identification.