PREPARATION AND APPLICATION PROPERTIES OF Ti-Si GLYCOL SALT CATALYSTS FOR POLYESTERS

Silicon catalysts have very low catalytic activity in polyester (PET). However, titanium catalysts have high catalytic activity in polyester. The simultaneous use of titanium and silicon catalysts is effective in reducing the activity of a single titanium catalytic base agent. In addition, the glycol salts of titanium and silicon (Ti-EG and Si-EG) prepared in the present invention for use in the polyester catalytic process can avoid the introduction of other groups of impurities during the polyester catalytic process, which would lead to premature capping of the polyester in the process of polycondensation and chain building and make it difficult to increase the molecular weight, and thus affect the quality of the polyester. It has been verified that the ratio of Ti:Si is 1:1 (mol), and total amount added to the catalyst is 0.15% of the raw material amount, and the polycondensation temperature was 260-280 °C for 60 min. Compared with the single Ti-EG catalyst, the b* value of the synthesized PET was significantly reduced, and the molecular weight and other indexes did not change too much. In addition, at the end of catalysis, the catalyst was uniformly dispersed in the reaction system, which could be used as a matting agent for PET.

Keywords:
catalyst; polymerization; polyester; activity