Kinetics of the polycondensation and copolycondensation of bis(3‐hydroxypropyl) terephthalate and bis(4‐hydroxybutyl) terephthalate

Abstract

The kinetics of the polycondensation and copolycondensation reactions of bis(3‐hydroxypropyl) terephthalate (BHPT) and bis(4‐hydroxybutyl) terephthalate (BHBT) as monomers were investigated at 270 °C in the presence of titanium tetrabutoxide as a catalyst. BHPT was prepared by the ester interchange reaction of dimethyl terephthalate and 1,3‐propanediol (1,3‐PD). Through the same method adopted for BHPT synthesis, BHBT was prepared with 1,4‐butanediol instead of 1,3‐PD. With second‐order kinetics applied for polycondensation, the rate constants of the polycondensation of BHPT and BHBT, k11 and k22, were calculated to be 4.08 and 4.18 min−1, respectively. The rate constants of the cross reactions in the copolycondensation of BHPT and BHBT, k12 and k21, were calculated with results obtained from proton nuclear magnetic resonance spectroscopy analysis. The rate constants during the copolycondensation of BHPT and BHBT at 270 °C decreased in the order k12 > k22 > k11 > k21, indicating that the reactivity of BHBT was larger than that of BHPT at 270 °C. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2435–2441, 2002

Characterization of poly(trimethylene/butylene terephthalate) copolymer prepared by the copolycondensation of bis(3‐hydroxypropyl terephthalate) and bis(4‐hydroxybutyl terephthalate)

“…The sequence length of the BT unit is longer than that of the PT unit, probably due to the reactivity of BT being higher than that of PT. This is in good agreement with our previous result19 showing the monomer reactivities calculated from the 1 H‐NMR peaks, which are 1.25 and 0.78 for BT and PT, respectively.…”

Synthesis and characterization of poly(ester carbonate)s by melt‐phase interchange reactions of dihydroxy compounds with alkylene and arylene diphenyl dicarbonates containing ester groups

“…Bis(4‐hydroxybutyl) cis/trans‐1,4‐cyclohexanedicarboxylate (CH–BuD) is a new compound and was obtained in high yield as a light yellow viscous liquid. The other two dihydroxy compounds, t ‐PHTH–BuD and t ‐PHTH–BPA were already known in the literature and were obtained in high yields as white solids. These compounds were characterized by melting point, FT‐IR, 1 H‐NMR, and 13 C‐NMR spectroscopy.…”

Kinetics of Ternary Copolycondensation for High-Performance PCTG Copolyester with Ester Interchange, Polycondensation, and Mass Transfer

“…The type of volatile small molecules is increased due to the introduction of the third monomer, especially when it is a diol, which further increases the modeling complexity of the copolycondensation process. Although a variety of studies have reported the polycondensation reaction kinetics of copolyesters and revealed that the ternary copolymerization process includes the homopolymerization reactions of the same binary prepolymers and the cross-polymerization reactions of different binary prepolymers, − the hydroxyl end-group concentrations and the relative reactivity of different terminal diols, as well as the mass transfer, were almost not considered during the polycondensation modeling.…”