Manufacturing method of polyether
I. Introduction
Polyether is an important class of raw materials for the production of chemicals, which is widely used in the fields of polyurethane, surfactants, lubricant additives and so on. With the continuous development of science and technology, the manufacturing method of polyether has been improved and optimized. This paper will introduce the manufacturing method of polyether in detail, including raw material preparation, polymerization reaction, post-treatment and other steps, in order to provide some guidance for the production of polyether.
II. Raw material preparation
1. Starting agent: commonly used starting agents are diols, ternary alcohols, such as ethylene glycol, propylene glycol, glycerol and so on. The choice of starting agent has a great influence on the performance of polyether, so it is necessary to choose a suitable starting agent according to the product use.
2. Ethylene oxide: Ethylene oxide is the main raw material for polyether production, it has high activity and can have ring-opening polymerization reaction with the initiator.
3. Catalyst: Commonly used catalysts in polyether production are alkali metal compounds and organometallic compounds, such as potassium hydroxide and sodium ethoxide. The role of the catalyst is to reduce the activation energy of the polymerization reaction, accelerate the reaction rate.
Three, polymerization reaction
Polymerization reaction is a key step in the production of polyether, mainly including the following stages:
1. initiation stage: under the action of the initiator, the initiator reacts with ethylene oxide to generate reactive intermediates.
2. Chain growth stage: the active intermediate continues to react with ethylene oxide to produce high molecular weight polyether.
3. Chain termination stage: when the molecular weight of the polyether reaches a certain degree, the active intermediate loses its activity and the polymerization reaction is terminated.
During the polymerization reaction, the reaction temperature, pressure, catalyst dosage and other factors need to be strictly controlled to ensure the stability of the molecular weight and molecular weight distribution of the polyether. At the same time, it is also necessary to carry out reasonable design and maintenance of the reaction equipment to ensure the safety and stable operation of the equipment.
Four, post-processing
After the polyether production is completed, post-processing is needed to get the final product. Post-treatment mainly includes the following steps:
1. Neutralization: use acidic substances to neutralize the catalyst in order to remove the alkaline components. Commonly used acids are sulfuric acid and hydrochloric acid.
2. Dehydration: Removing water from the polyether by methods such as distillation or vacuum drying to improve the purity of the product.
3. Filtration: Use filters to remove impurities and insoluble substances from the polyether.
4. Packing: Pack the polyether according to the specified requirements for transportation and storage.
V. Precautions
1. Safety first: In the process of polyether production, it is necessary to strictly abide by the safety operating procedures to ensure the safety of employees and equipment.
2. Quality control: It is necessary to carry out comprehensive quality control of polyether production process, including raw material inspection, process monitoring, product inspection and other links to ensure stable and reliable product quality.
3. Environmental protection requirements: In the production process, it is necessary to strengthen the treatment and emission control of waste gas, waste water and other pollutants to meet the environmental requirements.
VI. Conclusion
Polyether as a class of important raw materials for chemical production, its manufacturing method involves the control of several links and factors. Through reasonable raw material preparation, polymerization reaction and post-treatment steps, high-quality and high-performance polyether products can be produced. At the same time, the management and control of safety, quality and environmental protection need to be strengthened in the production process to ensure smooth production and high quality and reliable products.
