Dioctyl terephthalate (DOTP) is a widely used plasticizer, mainly used in polyvinyl chloride (PVC) and other plastic products. The following is the manufacturing method of Dioctyl Terephthalate:
I. Preparation of raw materials
The main raw materials for manufacturing Dioctyl Terephthalate are terephthalic acid and octanol. The quality of the raw materials has a great influence on the quality of the final product, so it is necessary to choose high-quality raw materials.
Two, esterification reaction
Add terephthalic acid and octanol into the reactor according to a certain molar ratio, heat and stir, so that the raw materials are fully mixed. Then add catalyst to promote the esterification reaction. The esterification reaction is a reversible reaction, which needs to control certain reaction conditions, such as temperature, pressure and amount of catalyst, to improve the conversion rate and selectivity of the reaction.
III. Dehydration reaction
After the esterification reaction, the reaction solution needs to be dehydrated to remove the water generated by the reaction. Vacuum distillation is usually used to vaporize the water from the reaction solution. Temperature and vacuum need to be controlled during dehydration to avoid decomposition and loss of products.
IV. Refining and purification
After the dehydration reaction, the product needs to be refined and purified to remove impurities and by-products from it. Usually distillation and filtration methods are used to purify the product to a certain purity.
V. Post-treatment
After the end of refining and purification, the product needs to be post-treated, such as adjusting the pH value, adding anti-oxidants, etc., in order to improve the stability and storage life of the product.
The above is the general method of manufacturing dioctyl terephthalate, the specific manufacturing process needs to be adjusted and optimized according to the actual situation. At the same time, attention needs to be paid to the safety and environmental protection of the manufacturing process to avoid harming the environment and operators.
All in all, the manufacture of dioctyl terephthalate requires the mastery of certain chemical reaction principles and chemical operation techniques, and at the same time, it needs to strictly control the production conditions and quality standards to ensure the quality and stability of the final product.
