A kind of nano-loaded titanium series composite catalyst and its preparation method and application in polyester synthesis

Abstract

The invention discloses a method for preparing a nano-loaded titanium-based composite catalyst. The titanium-based compound, tetraethyl orthosilicate and a hydrolyzing agent are dissolved in absolute ethanol, and stirred and reacted at room temperature for a certain period of time to obtain a mixed solution; Add one or more metal salts selected from chlorides, acetates or phosphates of Mg, Al, Mn, Co, Zn to the mixed solution, continue stirring, and heat up to volatilize excess solvent to obtain a gel; The gel is subjected to supercritical drying in the presence of a supercritical medium to obtain the final nano-loaded titanium-based composite catalyst. The catalyst prepared by the invention has strong hydrolysis resistance, can be stored for a long time, and has stable activity; has high catalytic activity and good stability, can effectively improve the efficiency of esterification and polycondensation reactions, has stable performance during the reaction process, and has stable product indicators; the catalyst is not Contains heavy metals, reducing the harm to the environment and human beings; the polyester prepared by using this catalyst has good hue, low yellow index and stable performance.

Description

technical field [0001] The invention relates to the field of polyester catalysts, in particular to a nano-loaded titanium-based composite catalyst, a preparation method thereof, and an application in polyester synthesis. Background technique [0002] Polyester, the general term for polymers obtained by polycondensation of polyols and polyacids, mainly refers to polyethylene terephthalate (PET), and customarily includes polybutylene terephthalate (PBT) and polyarylate, etc. Linear thermoplastic resin. Because of its excellent clothing application and high strength properties, it soon became the most productive variety in synthetic fibers. Due to its excellent comprehensive properties, it maintains excellent physical properties in a wide temperature range, high impact strength, friction resistance, good rigidity, high hardness, low hygroscopicity, good dimensional stability, and excellent electrical properties. It is resistant to most organic solvents and Inorganic acid is s...

AI Technical Summary

Problems solved by technology

Antimony-based catalysts have moderate activity and low price, so they are widely used in the polyester industry, but antimony compounds are heavy metals, which are harmful to human health and pollute the environment, and will gradually be replaced by other catalysts; The catalyst has good stability, less side reactions are caused during the reaction process, and the polyester produced has a good hue, but its catalytic activity is lower than that of the antimony series, and the obtained polyester has more ether bonds and a lower melting point, and the germanium resource Rare and expensive, there are economic limitations in practical applications, and there are few applications; titanium-based catalysts do not contain heavy metals, are safe and environmentally friendly, and have high catalytic activity and moderate prices. They are expected to replace antimony-based catalysts in the future

At present, there are many related research works on titanium-based catalysts, and some products have good applications in polyester, but titanium-based catalysts also have shortcomings, such as poor stability, easy hydrolysis, and more side reactions, and the product molecular weight distribution Unevenness, the color of the produced polyester products is yellowish, etc., which affects the application of titanium-based catalysts

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