纳米二氧化钛复合凹土催化剂的制备和催化聚酯反应

Preparation of Nano-TiO_2 Catalyst Supported on Attapulgite and Its Catalytic Performance in Polyester Synthesis

制备了一种以锐钛矿型为主的混晶纳米二氧化钛,并将其均匀复合于纳米凹凸棒土(ATP)上,得到了一类纳米复合催化剂,对二氧化钛及复合催化剂分别进行了X射线衍射和透射电镜表征。利用催化聚酯反应对二氧化钛及多种复合催化剂的性能进行了评价,结果表明,与常规聚酯催化剂Sb2O3相比较,纳米二氧化钛可达到与Sb2O3相近的催化活性,但催化性能不稳定,聚酯产品b值较高;将二氧化钛与纳米凹凸棒土复合后,催化性能更加稳定,同时也改善了聚酯的色相,b值从14.05降为8.17。此外,讨论了复合催化剂对聚酯产品物化性能的影响,通过DSC、TGA等测试手段,发现复合催化剂制备的聚酯结晶温度升高,二甘醇含量和热降解性能与常规聚酯相近。

A type of nano-TiO2 with the main structure of anatase crystal was prepared and supported on attapulgite. All these materials were characterized by means of XRD and TEM. The catalytic performance of the materials was evaluated by polyester reaction, and the results show that the catalytic activity of nano-TiO2 is close to that of Sb2 03. However, the catalytic property is unstable, and the hue b of polyester is larger; after the nano-TiO2 was supported on attapulgite, the catalytic center presented ideal dispersion state, the catalyst property was also more stable, and the hue b of polyester was better （ from 14.05 to 8. 17 ）. Besides, the physical and chemical properties of the polyester influenced by the TiO2-complex catalyst were discussed based on the analyses of DSC and TGA, and the results show that the crystallization temperature of polyester increased by using TiOz-eomplex catalyst, and the content of diethylene glycol and the thermal performance were close to those of normal polyester.