Terephthalic acid, neopentyl glycol and trimethylolpropane polyesterification using versatile and highly efficient tin complexes as catalysts precursors

Abstract

The catalytic performance of the tin complexes bis(acetylacetonato)tin(II) (1), dibutyltin oxide (2), bis(chloroacetato)tin(II) (3), bis(3-hydroxy-2-methyl-4-pyrona)tin(II) (4), dibenzoatotin(II) (5) and dihydroxybutyltin chloride (6) are described for terephthalic acid, neopentyl glycol and trimethylolpropane polyesterification. The synthesized complexes, which are easy to prepare from inexpensive commercial chemicals, showed catalytic behavior comparable to the industrially used (2) and (6). The productivity values varied from 72.2 when (2) was used as a catalyst to 192.0 with (1). The best values for reaction time was obtained for the commercial catalyst (6) (6 h 26 min) and for (1) (7 h 36 min). The infrared analyses allowed us to observe bands relative to ester formation and to confirm the hydroxylation for all polymers samples.