Ricci Giovanni - CNR - Istituto per lo Studio delle Macromolecole (ISMAC), via E. Bassini ۱۵, I-۲۰۱۳۳ Milano (Italy)
Leone Giuseppe

The stereospecifc polymerization of conjugated dienes began in 1954 with the frst catalysts obtained by combining TiCl4 or TiCl3 with aluminum-alkyls, i.e. the catalytic systems previously employed for ethyleneand propylene polymerizations. Subsequently, many other catalytic systems were obtained and examined by acombination of transition metal or lanthanide compounds with appropriate alkylating agents. With the advent ofMAO as alkylating agent, at the beginning of the 1980s, new catalytic systems were introduced, in some casesmuch more active and stereospecifc than those based on common aluminum-alkyls. Starting from the 2000s, in thewake of what happened in the case of mono-olefns, a new generation of catalysts based on complexes of transitionmetals and lanthanides with various ligands containing donor atoms such as P, N, O (e.g., phosphines, imines,imino-pyridines, cheto-imines) has been introduced. These systems have proved particularly active and able toprovide polymers with controlled microstructure (i.e., cis-1,4; 1,2; mixed cis-1,4/1,2 with a variable 1,2 content)from several types of 1,3-dienes, permitting indeed to establish new correlations between the catalyst structure,the monomer structure and the polymer microstructure, and to improve our knowledge on the polymerizationmechanism of 1,3-dienes. This paper provides an exhaustive overview of the latest developments in the feld ofstereospecifc polymerization of 1,3-butadiene. Polyolefns J (2014) 1:43-60

butadiene, catalysts, stereospecifc polymerization, polybutadiene