Following the green chemistry principles, three series of polyols with tailored chemical structures were obtained from PET wastes degradation via glycolysis and/or aminolysis and subsequent esterification-transesterification and/or amidation reactions, using an organic catalyst. As cleaving agents there were used various mixtures of renewable or potentially renewable reagents, selected from those that can be obtained from biomass by already applied or investigated and eventually patented biochemical and/or chemical processes. The polyols were characterized by physical-chemical methods, 1H-NMR, 13C-NMR and FT-IR Spectroscopy, and tested in the synthesis of rigid polyurethane foams, showing appropriate properties for spray foams formation and leading to materials with properties similar to conventional spray foams.
Metal-containing ionic liquids with general formula [Rmim]+MX3- (R=n-butyl or n-lauryl; M=Zn, Cd; X=Cl, Br) were synthesised and then characterized by nuclear magnetic resonance spectroscopy and infrared spectroscopy. The catalytic activity was tested in glycolysis of poly(ethylene terephthalate) (PET) with ethylene glycol (EG) with the main product being bis-2-hydroxyethyl terephthalate (BHET). The following parameters were varied: the catalyst type, the catalyst loading and the molar ratio between PET and EG. For every reaction conversion and selectivity were calculated. All these reactions arose with high selectivity in the desired product, the conversion of PET being quasi-total.
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