Effective aminolytic depolymerization of poly(ethylene terephthalate) waste and synthesis of bisoxazoline therefrom

Aminolytic depolymerization of postconsumer poly(ethylene terephthalate) (PET) bottle waste with 2-amino-2-methyl-1-propanol and 1-amino-2-propanol under atmospheric condition was investigated in the presence of catalysts zinc acetate or sodium acetate. The virtual products obtained in pure form were, respectively, bis(1-hydroxy-2-methylpropan-2-yl)terephthalamide and bis(2-hydroxypropyl)terephthalamide. The latter was taken for further studies because of its higher yield and subjected to cyclization using thionyl chloride under low-temperature conditions to get 1,4-bis(5-methyl-4,5-dihydrooxazol-2-yl)benzene, which is used as chain extender in polyester and nylon compositions and as a crosslinking agent in powder paint compositions. The products obtained from depolymerization were characterized by TLC, melting point, IR spectroscopy, 1H-NMR, 13C-NMR, and DSC. We have shown that it is possible to synthesize new utility products by recycling of PET waste. (C) 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012