Tributyl citrate (TBC), as one of the new generation of environmentally friendly plasticizers, has actually attracted attention from all over the globe. The US Food and Drug Administration (FDA) has actually approved its use in clinical gadgets, food product packaging products, kids’s toys and also personal hygiene items. TBC is a naturally degradable plasticizer with excellent compatibility, low volatility as well as high plasticizing efficiency. Additionally, it additionally has outstanding cool resistance, light resistance, water resistance as well as mildew resistance.
Tributyl citrate is widely used. In terms of food, medicine and instrument packaging, because TBC has the advantages of good compatibility with polyvinyl chloride (PVC) and high plasticizing efficiency, the PVC film plasticized with TBC has a good performance. The air permeability and water permeability can keep meat fresh and prolong the freshness period of vegetables; in the pharmaceutical industry, adding TBC as a carrier to medicine can make the outer surface of the medicine strong and not easy to break, and its existence can make the medicine in the It can be slowly released in the body at a certain rate within a certain period of time to maintain the effective concentration of the drug in the blood and achieve the purpose of effective treatment; in terms of biodegradation, adding appropriate TBC to the degradable polymer material can make the polymer change from rigid chain to It is a flexible chain and gives it machinability.
In addition, tributyl citrate can also be used as a raw material for the production of another environmentally friendly plasticizer, acetyl tributyl citrate (ATBC). The synthesis of TBC and dioctyl phthalate is obtained by the esterification reaction of acid and alcohol under the action of a catalyst. Traditional esterification reactions generally use concentrated sulfuric acid as a catalyst, which can fully contact with the reactants. And the catalytic activity is high, and the cost is relatively low; however, concentrated sulfuric acid has many disadvantages as a catalyst, such as difficulty in separating from the product, many side reactions, corrosion of equipment and environmental pollution. Therefore, the research and development of new environmentally friendly catalysts has become the focus of attention.
Compared with liquid acid catalysts, solid acid catalysts have their outstanding advantages: (1) easy to separate from the product after the reaction; (2) easy to regenerate and reusable; (3) easy to achieve continuous production; (4) The equipment is non-corrosive; (5) easy to store and handle; (6) green and pollution-free. Based on the above advantages, people continue to develop new solid acid catalysts and catalytic processes to meet the needs of laboratories and industries, and solid acid catalysts have also been widely used.
At the same time, solid acid catalysts also have some disadvantages: (1) The catalytic activity of solid acid is not as good as that of liquid acid catalysts such as sulfuric acid; (2) The thermal stability of solid acid is poor, and it is easy to deactivate during the reaction, making the catalytic The life is shortened; (3) For some specific reactions, solid acids cannot meet the demand because of their different acid strengths; (4) The price is higher. For example, the above-mentioned problems have been encountered during the use of strongly acidic cation exchange resins. On the one hand, their catalytic activity is not high enough;
On the other hand, it is heat-resistant and stable. The use temperature is limited below 120°C. When the temperature is higher than this temperature, the catalyst is easy to collapse, and it is easy to lose the catalytic sulfonic acid group, resulting in catalyst deactivation. These deficiencies limit the application of solid acid catalysts. In order to make full use of the unparalleled advantages of solid acid, it is necessary to develop new methods and new routes, overcome the shortcomings and shortcomings of solid acid, and improve it to expand its industrial application.
