Abstract:
A novel hydrolysis-resistant titanium-based catalysts (TC) were synthesized via coordination reaction, utilizing tetrabutyl titanate (TBT) as the titanium source and citric acid (CA) as the chelating agent. In comparison with traditional TBT catalyst, the effects of process parameters such as TC content on key parameters of PBT products during synthesis were investigated in detail, including the terminal carboxyl group content (―COOH), intrinsic viscosity (
η), and the content of tetrahydrofuran (THF) in the esterification solution. The results demonstrated that the optimal PBT performance was achieved when the addition amount of TC catalyst is 2% (
vs. p-phthalic acid), temploying esterification at 230℃ for 2 h, and the polycondensation at 255℃ for 2.5 h. For example, the
η reached as high as 0.76 dL·g
−1, indicating that the product has a high molecular weight and good mechanical properties; the content of ―COOH was as low as 27.88 mmol·kg
−1, demonstrating superior hydrolysis resistance; the THF content was only 8.86%, indicating that side reactions has been effectively suppressed and the utilization rate of raw materials has been improved. Furthermore, the hydrolysis test demonstrated that the TC catalyst still exhibited excellent hydrolysis resistance under high-temperature and high-humidity conditions. In conclusion, the self-developed titanium-based catalysts demonstrate significant advantages in enhancing the quality of PBT products, reducing production energy consumption, and improving the stability of the materials, showing a promising potential for industrial applications in high-performance polyester materials.