【摘要】 为解决聚酯合成中锡锑金属基催化剂的有毒性以及钛基金属催化剂易导致聚酯黄变等难题，利用蒙脱土（MMT）的层间开放性以及易吸附性，开发了一种以钠基MMT（Na-MMT）为基体，通过离子交换引入Zn²⁺、Al³⁺提高NaMMT的催化活性，并以锌离子交换MMT（Zn-MMT）、铝离子交换MMT（Al-MMT）和Na-MMT为催化剂催化合成聚对苯二甲酸丙二酯（PTT）的方法。通过X射线荧光光谱仪、X射线衍射仪、傅里叶变换红外光谱仪等对催化剂的结构进行了表征，发现Al-MMT和Na-MMT的孔道结构变化较小，而Zn-MMT的比表面积与孔容降低，孔径增大，有利于反应物分子与活性位点接触，因此Zn-MMT催化活性最高，最佳反应条件为Zn-MMT质量分数为0.08%、缩聚温度为260℃、缩聚时间为2.5 h，制得的PTT特性黏度为0.919 dL/g，端羧基含量为17.416 mol/t。与钛酸丁酯相比，Zn-MMT合成的PTT特性黏度增大19.5%，端羧基含量降低49.79%，其原因是铝元素的存在弥补了锌元素聚合与解聚的活性差异。更多还原

【Abstract】 To address the problems such as the toxicity of tin-antimony metal-based catalysts in polyester synthesis and the yellowing of polyester caused by titanium-based metal catalysts, taking advantage of the interlayer openness and easy adsorption of montmorillonite（MMT）, a method was developed, in which sodium-based MMT（Na-MMT） was used as the matrix, Zn²⁺ and Al³⁺ were introduced through ion exchange to enhance the catalytic activity of Na-MMT and polypropylene terephthalate（PTT） was catalytically synthesized by using zinc ion-exchange montmorillonite（Zn-MMT）, aluminum ion-exchange montmorillonite（Al-MMT） and Na-MMT as catalysts. The structure of the catalyst was characterized by X-ray fluorescence spectrometer, X-ray difftometer, Fourier transform infrared spectrometer, and etc. It is found that the pore structure changes of Al-MMT and Na-MMT are relatively small, while the specific surface area and pore volume of Zn-MMT decrease and the pore diameter increases, which is conducive to the contact between reactant molecules and active sites. Therefore, Zn-MMT has the highest catalytic activity. The optimal reaction conditions are that the dosage of Zn-MMT is 0.08 wt%, the polycondensation temperature is 260 ℃, and the polycondensation time is 2.5 h. The characteristic viscosity of the prepared PTT is 0.919 dL/g, and the content of terminal carboxyl groups is 17.416 mol/t. Compared with butyl titanate, the intrinsic viscosity of PTT synthesized by Zn-MMT is increased by 19.5%, while the content of terminal carboxyl groups decreased by 49.79%. The reason is that the presence of aluminum element compensates for the difference in polymerization and depolymerization activity of zinc element.更多还原