Cooling method for isoprene rubber polymerization reaction

Abstract

The invention relates to a cooling method for an isoprene rubber polymerization reaction. In a polymerization reaction kettle with a double helical ribbon agitator, a plurality of radial push type scrapers closely matched with a kettle wall are added between ribbons on external sides of double helical ribbon agitator blades; a frictioning direction of the radial push type scrapers and a stirring tangent direction form an angle of 30-60 DEG; adjacent radial pushing type scrapers are uniformly distributed in 30-180 DEG; the radial pushing type scrapers are fixed on a fixed bracket; and the fixed bracket is fixed on an agitating shaft between the ribbons of the double helical ribbon agitator blades, and can rotate coaxially with the double helical ribbon agitator blades. When isoprene is subjected to a continuous polymerization reaction under effect of rare earth catalyst, and a conversion rate reaches 50%, the push type scrapers are used to clean high-viscosity glue attached to the polymerization reaction kettle wall in the polymerization process, so as to control a polymerization reaction temperature at 44-46 DEG C. The method reduces thermal resistance at the kettle wall, improves mass transfer and heat transfer of a high viscosity system in later stage of the polymerization reaction and realizes a smooth and controllable temperature.

Description

Technical field: [0001] The invention relates to a heat removal method for a high-viscosity system in the late stage of the polymerization reaction of rare earth isoprene rubber. Background technique [0002] Isoprene rubber is a high cis (cis-1,4 content of 95% to 98%) synthetic rubber made from isoprene. Its structure and properties are similar to those of natural rubber. It is also called synthetic natural rubber. Instead of natural rubber, it is used in tire manufacturing and medicine. [0003] The preparation of isoprene rubber by isoprene solution polymerization is an exothermic reaction. As the polymerization reaction progresses, the viscosity of the reaction material becomes larger and larger, and the reaction material is a high-viscosity system in the late stage of the polymerization reaction. Therefore, how to quickly remove the reaction heat in the isoprene rubber high-viscosity system is a key technology to ensure the smooth operation of the production device and produ...

AI Technical Summary

Problems solved by technology

[0004] The existing technology can effectively remove the heat of reaction during the initial and middle stages of the isoprene polymerization reaction to ensure that the temperature is stable and controllable. The more difficult it is, especially in the later stage of polymerization, the glue is a high-viscosity system, which cannot remove the heat of reaction in time and effectively, and it is difficult to control the polymerization temperature at the set value

It is possible to increase the heat transfer area by increasing the number of serial kettles and adopting external circulation of the kettle, but it will increase power consumption, which is unfavorable for large-scale production, and the rare earth isoprene rubber is a high-viscosity system in the later stage of the polymerization reaction, and it is difficult to realize the withdrawal of the external circulation of the kettle. hot

Filling cold solvent can effectively achieve the purpose of heat removal, but the experiment found that the viscosity of rare earth isoprene rubber is too high in the later stage of polymerization, and the cold solvent cannot mix well with the glue. On the one hand, the heat removal effect becomes poor, and on the other hand, it causes temperature difference Large, uneven temperature distribution affects the polymerization reaction