Reflecting on the importance of sustainable development, polymers are a major issue. This work focuses on the synthesis, decomposition and recycling of polyenaminones and polyurethanes. Polyenaminones were synthesized by a relatively new method from bisenaminones and aromatic diamine salts by vinylogous nucleophilic substitution polymerization. The obtained oligomers and polymers of enaminone type were characterized by 1H NMR and IR spectroscopy and molecular characteristics were determined. Chemical recycling was carried out at elevated temperature with excess dimethylamine in ethanol. Depolymerization products were separated and high recycling yields were obtained. Spontaneous polymerization in solid was observed if the evaporated reaction mixture was allowed to stand at room temperature for 24 h after depolymerization.
Polyurethanes were synthesized in solid from diisocyanates and polyols in the presence of a catalyst by addition polymerization. The polymers were characterized by 1H NMR spectroscopy, IR spectroscopy and elemental analysis. Comparative biodegradability tests with respirometry were performed. Assimilated bacteria were used for faster degradation. We compared the synthesized polymers with classic non-biodegradable polymers and observed a high relative increase in degradability. We were also interested in thermal decomposition products and the behavior of the polymer with increasing temperature, so we performed Py-GC/MS and DSC measurements. All polymers decomposed into the starting diisocyanates, polyol fragments and aliphatic amines. In most products, a glass transition at temperatures below 150 °C was observed, only in one case a melting point appeared.
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