Study Of Poly (Trimethylene Terephthalate) Polymerization Catalysts

Poly (trimethylene terephthalate)(PTT) is a new type of polyester material, because its high performance, which has been widely used in fiber, engineering plastic fields and many other domains. Combined with the advantages of PBT and PET, the foreground of the application of PTT would have a huge market. There are two PTT preparation methods, the ester exchange and direct esterification. In this paper the direct esterification method was used. The task is highly active PTT polymerization catalysts preparation by means of direct esterification method to use PTA and PDO as raw material direct esterification synthesis of PTT. Two aspects were under consideration:one is organic titanium system catalyst, the other is inorganic composite catalyst. Firstly, organic titanium catalyst structure was changed to improve the traditional organic titanium system catalyst stability and activity. Acetyl acetone base was added to synthesis acetyl acetone titanium to enhance catalytic stability. Also we used oxygen to replace the acetyl acetone base to minimize space steric hindrance to improve activity. Secondly, due to the inorganic composite oxide have higher stability, so the preparation of highly active inorganic composite catalyst was choosed. In this paper sol-gel method was used to mixed titanium oxide and silicon oxide into composite nanoparticles. And then, exa mined the activity of catalyst, compared the products’ viscosity, and optimized the process conditions. Finally, used FT-IR and1H-NMR to characterization organic titanium catalyst structure, with TEM representation inorganic composite catalyst structure form, and XRD characterization of the catalyst crystal type and calculate its size.