PROCEDURE FOR THE PREPARATION OF POLICE SUBSTANCES TO PREVIOUSLY ALTERNATED CIS-1,4-ALT-3,4 IN THE PRESENCE OF A CATALYTICAL SYSTEM COMPATING A PIRICAL FERREN COMPLEX

摘要

Process for the preparation of polyisoprene with a mainly alternating cis-1,4-alt-3,4 structure comprising polymerizing isoprene in the presence of a catalytic system comprising: (a) at least one pyridyl iron complex having general formula (I): wherein: - R1 is selected from linear or branched C1-C20, preferably C1-C15, alkyl groups, optionally substituted cycloalkyl groups, optionally substituted aryl groups; - R2 is selected from linear or branched C1-C10, preferably C1-C3, alkyl groups; - X, mutually identical or different, represent a halogen atom such as, for example, chlorine, bromine, iodine; or they are selected from linear or branched C1-C20, preferably C1-C15, alkyl groups, -OCOR3 groups or -OR3 groups wherein R3 is selected from linear or branched C1-C20, preferably C1-C15, alkyl groups, - n is 2 or 3; (b) at feast one co-catalyst selected from organo-derivative compounds of aluminum, preferably from (b1) aluminoxanes having general formula (II): ( R4)2-AI-0-[-AI(R5)-0-}m-AI-(R6)2 ( II ) wherein R4, R5 and R6, mutually identical or different, represent a hydrogen atom, or a halogen atom such as, for example, chlorine, bromine, iodine, fluorine; or they are selected from linear or branched C1-C20 alkyl groups, cycloalkyl groups, aryl groups, said groups being optionally substituted with one or more silicon or germanium atoms; and m is an integer ranging from 0 to 1000; (b2) aluminum compounds having general formula (III): AI(R7)(R8)(R9) (III) wherein R7 is a hydrogen atom, or is selected from linear or branched C1-C20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, arylalkyl groups, alkoxy groups; R8 and R9, mutually identical or different, are selected from linear or branched C1-C20 alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, arylalkyl groups; wherein the molar ratio between the aluminum present in the co-catalyst and the iron present in the iron pyridyl complex having general formula (I) is ranging from 5 to 60, preferably from 8 to 55.