The catalytic effect of polyester knitted fabric polymerization reaction

The selection and optimization of catalysts are crucial in the production of polyester knitted fabrics. Different catalysts have varying effects on polymerization reactions, so it is necessary to choose the appropriate type and dosage of catalyst based on specific production processes, raw material quality, and product performance requirements.
Types of catalysts
The commonly used catalysts for polymerization reactions in polyester production are mainly divided into two categories: metal catalysts and non-metal catalysts. Antimony based catalysts are very common among metal catalysts, such as antimony trioxide, antimony acetate, antimony glycol, etc. These catalysts are widely used due to their high efficiency, stability, and moderate cost. In addition, titanium based and germanium based catalysts are also used under certain specific conditions. Non metallic catalysts include organic phosphorus compounds, organic sulfonic acids, and their salts, which exhibit unique catalytic effects under certain special requirements.
Mechanism of catalyst action
Reduce activation energy: Catalysts provide a low-energy reaction pathway, allowing reactant molecules to collide effectively at lower energies, thereby initiating polymerization reactions. This process significantly reduces the activation energy of the reaction, allowing the polymerization reaction to proceed rapidly under milder conditions.
Promoting esterification reaction: In the esterification stage of polyester production, catalysts accelerate ester exchange or direct esterification reactions to promote the binding between monomers such as PTA and MEG, forming polyester prepolymers. The selection and dosage of catalyst have a significant impact on the rate and degree of esterification reaction.
Influence on polymerization degree and molecular weight distribution: The type and concentration of catalyst also affect the polymerization degree of the polymerization reaction and the molecular weight distribution of the final product. Efficient catalysts can promote more complete reactions, increase polymerization degree, and potentially produce a narrower molecular weight distribution range, thereby enhancing the performance of polyester fibers.