Synthesis of Unsaturated Polyester Resins from PET Wastes: Effect of a Novel Co-catalytic System on Glycolysis and Polyesteriflcation Reactions

摘要

Poly(ethylene terephthalate) (PET) waste materials were depolymerized by propylene glycol (PG) in presence of a novel catalytic system (zinc acetate with cyclohexylamine as a co-catalyst) and the effect of co-catalytic system on glycolysis reaction was compared with that of a commonly used catalytic compound (zinc acetate). The glycolyzed product was reacted with maleic anhydride (MA) and phthalic anhydride (PA) to prepare unsaturated polyester resin. The characteristics of the reaction products in each step were studied by ~1H-NMR, FT-IR, GPC and intrinsic viscosity (IV). It was found that the depolymerization of PET bottles in the presence of co-catalytic system proceeded faster compared with zinc acetate-catalyzed reaction. Moreover, in synthesis of unsaturated polyester resins, it was observed that the reaction rate of glycolyzed ingredients prepared by co-catalytic system with anhydrides was higher than that of glycolyzed product made by zinc acetate. It was concluded that cyclohexyleamine has a catalytic effect on unsaturated polyester resin synthesis.