METHOD FOR PARTIAL HYDROGENATION OF STATISTICAL COPOLIMERS OF VINYLAROMATIC COMPOUNDS AND CONJUGATED DIENES

摘要

1. A method for partial hydrogenation of random copolymers of vinyl aromatic compounds and conjugated dienes, both linear and branched, where the term “branched” means copolymers in which the macromolecules are bonded to each other via carbon-carbon bonds, and in which the branches mainly relate to high chains or a very high molecular weight, the aforementioned random copolymers being prepared in solution in the presence of 2-methoxyethyl tetrahydrofuran (THFA-ethyl) as a randomizing agent , The method comprising! the reaction of a random copolymer of a vinyl aromatic compound and a conjugated diene dissolved in a hydrocarbon solvent with hydrogen in the presence of a titanium complex and an alkylating agent to achieve the desired degree of hydrogenation, the method being characterized in that the alkylating agent is selected from compounds having the general formula MgR1R2,! where R1 and R2, the same or different, are selected from alkyl radicals having from 1 to 12 carbon atoms. ! 2. The method according to claim 1, where R1 and R2, the same or different, are selected from alkyl radicals having from 2 to 8 carbon atoms. ! 3. The method according to claim 1, where the vinyl aromatic compound is styrene, and the conjugated diene is 1,3-butadiene. ! 4. The method according to claim 1, where the partial hydrogenation is carried out at a pressure of from 400 to 2000 kPa and a temperature of from 70 to 150 ° C. ! 5. The method according to claim 4, where partial hydrogenation is carried out at a pressure of from 500 to 1500 kPa and a temperature of from 80 to 110 ° C. ! 6. The method according to claim 1, where the degree of hydrogenation is from 20 to 90%, preferably from 25 to 85%. ! 7. The method according to