Manufacturing method of sorbitol initiator hard foam polyether polyol
I. INTRODUCTION
Sorbitol initiator hard foam polyether polyol is an important raw material for the production of chemicals, which is widely used in the fields of polyurethane hard foam, thermal insulation materials, coatings and so on. This paper will introduce the manufacturing method of sorbitol starter hard foam polyether polyol, including raw material preparation, reaction process, post-treatment and other processes.
2. Raw material preparation
1. Sorbitol: as a starting agent, sorbitol has multiple hydroxyl groups, which can have ring-opening polymerization reaction with raw materials such as ethylene oxide. Ethylene oxide: as a polymerization monomer, ethylene oxide can react with sorbitol in ring-opening polymerization to produce polyether polyol.
3. Catalyst: Alkaline catalysts, such as potassium hydroxide or sodium hydroxide, are usually used to promote the ring-opening polymerization reaction.
3. Reaction process
1. Pre-treatment: Add sorbitol and catalyst into the reactor, and heat it to a certain temperature, so as to dissolve the catalyst and mix it with sorbitol sufficiently.
2. Polymerization reaction: under the action of stirring, gradually add ethylene oxide, so that it and sorbitol ring-opening polymerization reaction. Temperature, pressure and dosing rate need to be controlled during the reaction to ensure the smooth progress of the reaction.
3. Post-treatment: After the reaction, the products are neutralized, washed and dehydrated to remove the catalyst and by-products.
4. Influencing factors and control
1. Temperature: Temperature has a great influence on the speed of polymerization reaction and the molecular weight of the product. It usually needs to be controlled within a certain temperature range to obtain ideal product properties.
2. Pressure: Pressure mainly affects the boiling point and reaction rate of ethylene oxide. The reaction needs to be carried out at the proper pressure to ensure the smooth progress of the reaction.
3. Charging rate: The charging rate has a great influence on the molecular weight and molecular weight distribution of the product. It is necessary to control the appropriate charging rate to obtain the ideal product properties.
V. Post-treatment and product quality control
1. Neutralization: Use acid to neutralize the residual alkaline catalyst to ensure the stability and usability of the product.
2. Washing: Wash the product with water to remove by-products and residual raw materials.
3. Dewatering: Use vacuum drying or centrifugal dehydration and other methods to remove water from the product to ensure the quality and storage stability.
VI. Safe production and environmental protection requirements
1. Safe production: In the production process, it is necessary to strictly follow the safety operation regulations to ensure the normal operation of the equipment and avoid the occurrence of safety accidents.
2. Environmental Protection Requirements: Waste water, exhaust gas and other pollutants generated in the production process need to be treated to meet environmental standards and then discharged to reduce the impact on the environment.
VII. Conclusion
The manufacturing method of sorbitol initiator hard foam polyether polyol involves the control of multiple processes and influencing factors, which requires strict mastery of the process parameters and operating points of each link to ensure the quality of the product and the safety and environmental protection of the production. Through reasonable process design and operation control, sorbitol starter hard foam polyether polyol with excellent performance can be produced, providing high quality raw materials for polyurethane hard foam and other fields.
