Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

TEREPHTHALIC ACID, NEOPENTYL GLYCOL AND TRIMETHYLOLPROPANE POLYESTERIFICATION USING VERSATILE AND HIGHLY EFFICIENT TIN COMPLEXES AS CATALYSTS PRECURSORS

2001; De Gruyter; Volume: 24; Issue: 7 Linguagem: Inglês

10.1515/mgmc.2001.24.7.435

2191-0219

Ana. B. de Oliveira, Paulo A. Z. Suarez, Nara Regina de Souza Basso, Sandra Einloft,

Analytical Chemistry and Chromatography

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. INTRODUTIONPolyesters have been widely used as polymeric materials.Indeed, terephthalic acid based polyesters have received special attention due to several interesting properties of Polyethylene terephthalate) or PET.This polyester is the most widely used synthetic fiber which is sold under many different trade names.PET is also commonly encountered in plastic bottles for soft drinks and in films which are used for food or liquid packaging, magnetic tapes and novelty balloons, among others applications [1], Polyesters based on isophthalic acid and terephthalic acid have been developed for use in polyester powder coatings [2].Terephthalic acid has historically been the primary monomer providing polymers with the required glass transition temperature for coating storage stability, while contributing flexibility, weathering and chemical resistance [2].Different metallic ions have been described that catalyse efficiently esterification and polyesterification reactions.Nondek and Mälek [3] ordered the activities of catalysts for reaction of ethylene glycol with isophthalic acid as Sn +2 > Ti 4+ »Zn + >Pb 2+ ,Co 2+ ,Cd 2+ .The development of simple and cheaper catalytic systems for polyesterification reaction as well as new polymer materials using different monomers is important for technological and academic purposes.We have recently shown that the tin complex, bis(3hydroxy-2-methyl-4-pyrona)tin(II) (4), is highly active as polyesterification catalyst [4], In this paper we wish to report highly efficient catalysts systems based upon tin complexes, using differents ligands, for terephthalic acid (TFA), neopentyl glycol (NPG) and trimethylolpropane (TMP) polyesterification.