Synthesis of poly（ethylene terephthalate） catalyzed by MIL⁃53⁃OHx

doi:10.19491/j.issn.1001-9278.2025.11.010

Abstract

Abstract:

This study reports the synthesis of Al⁃MIL⁃53⁃OH_x materials with varying hydroxyl group ratios and their application as catalysts in the production of poly（ethylene terephthalate）（PET）. The catalysts were characterized for their thermal stability and structure using techniques including Fourier⁃transform infrared spectroscopy， thermogravimetric analysis， X⁃ray diffraction， transmission electron microscopy， and N₂ low⁃temperature physisorption. The influence of key synthesis parameters， namely catalyst dosage， polycondensation time， and polycondensation temperature， on the intrinsic viscosity and molecular weight of the resulting PET was systematically investigated. The results demonstrated that the introduction of hydroxyl groups into the MIL⁃53 framework significantly enhanced catalytic activity， leading to a substantial reduction in the required reaction time.

Key words: MIL?53?OH_x, poly （ethylene terephthalate）, polycondensation reaction, aluminum?based catalyst, viscosity

CLC Number:

TQ323.4

WANG Ji, BAI Wei, WU Wenhui, WANG Qingyin, WANG Gongying. Synthesis of poly（ethylene terephthalate） catalyzed by MIL⁃53⁃OH_x[J]. China Plastics, 2025, 39(11): 59-65.

Figures/Tables 12

Fig. 1. The molecular structure of PET

Fig. 2. The XRD pattern of Al⁃MIL⁃53⁃OHx

Fig.3. TEM of Al⁃MIL⁃53⁃OHx

Fig.4. IR spectra of Al⁃MIL⁃53⁃OHx

Fig.5. N2 adsorption and desorption isotherm of Al⁃MIL⁃53⁃OHx

样品	BET 比表面积/m²·g^-1	t⁃Plot 微孔体积/ cm³·g^-1	平均孔径/nm
Al⁃MIL⁃53⁃OH₂₅	875	0.35	1.7
Al⁃MIL⁃53⁃OH₅₀	708	0.31	1.5
Al⁃MIL⁃53⁃OH₇₅	398	0.18	1.2
Al⁃MIL⁃53⁃OH₁₀₀	89	-	-

Tab.1. Specific surface area of Al⁃MIL⁃53⁃OHx

Fig.6. TGA curve of Al⁃MIL⁃53⁃OHx

Fig.7. The effects of catalyst amount on the properties of PET synthesized

Fig.8. The effects of polycondensation time on the properties of PET synthesized

Fig.9. The effects of polycondensation temperature on the intrinsic viscosity of PET

Fig.10. Stress⁃strain curves curve of PET obtained by different catalysis

Fig.11. The proposed mechanism of the PET syntheses catalyzed by MIL⁃53⁃OH x

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