Abstract
Oligomers of bis(2-hydroxyethyl terephthalate) (BHET) was obtained by glycolysis of PET applying a simplified method. PET glycolysis was carried out in presence of ethylene glycol (EG) at reflux temperature, PET:EG molar ratio of 1:3 and 0.1 wt.% of catalyst. Metal compounds based on acetates and acetylacetonates of Zn, Mn, Pb, Co, Cu and Sm were used as catalyst. Molecular weights (MW) of these oligomers were determined by size exclusion chromatography (SEC). Gaussian deconvolution of SEC curves used to evaluate the oligomers composition generated with each catalyst showed that reactions carried out in presence of zinc acetate, lead acetate and manganese acetylacetonate lead to oligomers with the lowest molecular weights, predominating monomer and dimer of BHET. DSC traces showed that the melting behavior of these oligomers are highly dependent on the MW composition and in all cases multimodal profiles with melting peaks ranging from 80 to 155 °C were obtained.
Get full access to this article
View all access options for this article.