Catalyst for producing polybutylene succinate or copolyester thereof, and preparing mehtods of the catalyst

Abstract

The present invention provides a catalyst used in the production of PBS or its copolyesters and the preparation method thereof. The method comprises the following steps: (1) adding titanium alkoxide, silicon alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system; (2) adding complexing agent into the reaction system, then collecting catalyst from the products obtained in this step. Moreover, the method may comprises steps of: (1) adding titanium alkoxide, dihydric alcohol and metal co-catalyst into the solvent and conducting the reaction at a temperature of about 80° C. to 180° C., then removing the unreacted materials and small molecular products in the reaction system; (2) adding silicon alkoxide and complexing agent into the reaction system, then collecting catalyst from the products obtained in this step. The catalyst in the present invention has higher activity and thus the catalyst additional amount is reduced which will improve the quality of the products. Moreover, the catalyst in the present invention could be used alone in the production of PBS or its copolyester without the need for other materials and it won't react with water and thus could be stored for a long time. In sum, the catalyst in the present invention has a broad prospect in industrial application.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a catalyst used in the production of PBS or its copolyesters and the preparation method thereof.BACKGROUND OF THE INVENTION[0002]Aliphatic polyesters has aroused wide attention and research from domestic and foreign scholars because of their great biodegradable and environmentally non-persistent properties. Aliphatic polyesters and in particular poly (butylene succinate) (PBS) even have additional advantage features, such as good mechanical and processing properties. Therefore, PBS, which has enormous application prospect, becomes the focus of attention in industry recently.[0003]Previous attempts at the production of PBS or its copolyesters are generally fall into two kinds of production processes, chain extending process and direct polycondensation process. In the chain extending process, chain extender is added into the reaction system to react with the organic groups of the polyesters in order to increase molecular wei...