Study of various catalysts in the synthesis of poly (propylene terephthalate) and mathematical modeling of the esterification reaction

摘要

Pure terephthalic acid (TPA) was esterified with 1,3-propanediol (1,3-PDO) in the presence of various catalysts, in order to find the most effective one for this esterification reaction. The prepared oligomers were polycondensated in a second step under high vacuum and using the same catalyst (Sb(OCOCH_3)_3, Ti(OC_4H_9)_4, GeO_2) as before, or the well known catalyst for poly (ethylene terephthalate) (PET) production technology Sb_2O_3. The esterification reaction was monitored by measuring distilled water as a function of time and from these data the modeling of this process was carried out. The received poly (propylene terephthalate) (PPT) samples were characterized by viscometry, carboxyl end-group content and color measurement. From this study, tetrabutoxytitanium was proved to be the most effective catalyst for the esterification reaction. When this catalyst was used in the second step a PPT polymer with the highest molecular weight was received.