Abstract: To address issues of yellowish color and inefficient viscosity increment of slice prepared by traditional titanium catalyst, a new-type titanium-based catalyst was prepared. A polyester slice with good color and low by-product content was successfully prepared based on the titanium-based catalyst. The slice can also be further used to prepare high-viscosity slices for industrial yarns through solid-phase polycondensation. Through polymerization of the self-prepared new titanium catalyst, a polyester slice with a viscosity of about 0.65 dL/g at a lower dosage (2.5×10^-5)was obtained. Its properties were studied using Ubbelohde viscometer, volumetric titration, DSC thermal analysis, etc. The results indicated that the polyester prepared by this means was good in color, with b value of as low as 1.17, much lower than that prepared by the existing titanium catalyst (b value is 5.55). The carboxyl terminal concentration of the polyester was 16 mol/t, and the mass fraction of oligomer was about 2.0%. In addition, after solid-phase polycondensation at 230 ℃ for 8 h, its intrinsic viscosity reached 1.10 dL/g, with high efficiency in viscosity increment. This study can provide a useful reference for the large-scale application of titanium-based catalysts in polyesters.

Key words: polyester, titanium catalyst, color value, property, solid phase polycondensation

摘要： 为了改善传统钛系催化剂制得切片色泽泛黄、增黏效率低的问题,自制了一种新型钛系催化剂。利用该钛系催化剂成功制备了色泽良好、副产物含量低的聚酯切片,而且该切片还可进一步用于固相缩聚制得工业丝高黏切片。自制新型钛系催化剂在较低用量(2.5×10^-5)时可聚合得到黏度为0.65 dL/g左右的聚酯切片,通过乌氏黏度计、容量滴定法、DSC热分析等对其性能进行研究。结果表明:所制备的聚酯色相良好,其b值最低可达1.17,远低于现有钛系催化剂制备的聚酯切片(b值为5.55),聚酯的端羧基浓度为16 mol/t,低聚物质量分数在2.0%左右。同时,聚酯切片在230 ℃固相缩聚8 h后,其特性黏度可达1.10 dL/g,增黏效率高,为钛系催化剂在聚酯规模化应用提供有益参考。

关键词: 钛系催化剂, 聚酯, 色值, 性能, 固相缩聚