PROCESS FOR THE PREPARATION OF SYNDIOTACTIC 1,2-POLYBUTADIENE IN THE PRESENCE OF A CATALYTIC SYSTEM COMPRISING A PYRIDYL IRON COMPLEX

摘要

Process for the preparation of syndiotactic 1,2-polybutadiene comprising polymerising 1,3-butadiene in the presence of a catalytic system comprising: - at least one pyridyl iron complex having the general formula (I), in which: - R1 represents a hydrogen atom; or a methyl group; - R2 represents a hydrogen atom; or is selected from linear or branched C1-C10, preferably C1-C3, alkyl groups; - X, identical or different to one another, represent a halogen atom such as, for example, chlorine, bromine, iodine; or are selected from linear or branched, C1-C20, preferably C1-C15, alkyl groups, -OCOR3 groups or -OR3 groups in which R3 is selected from linear or branched C1-C20, preferably C1-C15, alkyl groups; - n is 2 or 3; - at least one aluminoxane having the general formula (II), (R4)2-AI-O-[-AI(R5)-O-]m-AI-(R6)2 (ll) in which R4, R5 and R6, identical or different to one another, represent a hydrogen atom, or a halogen atom such as, for example, chlorine, bromine, iodine, fluorine; or are selected from linear or branched C1-C20 alkyl groups, cycloalkyi groups, aryl groups, said groups being optionally substituted with one or more silicon atoms or germanium; and m is an integer ranging from 0 to 1000; in which the molar ratio between the aluminium present in the aluminoxane having the general formula (II) and the iron present in the pyridyl iron complex having the general formula (I) is ranging from 5 to 20, preferably ranging from 8 to 12.