The stereospecific polymerization of 1,3-dienes with transition metal and lanthanide catalysts can give polymers with different structure (cis-1,4; trans-1,4; 1,2; 3,4; iso- and syndiotactic) from different monomers1. The polymer microstructure mainly depends on the catalyst and monomer structures, and particularly on the combination of these two factors. Thus for instance, the classical ternary system AlEt2Cl/Nd(OCOC7H15)3/Al(iBu)3 gives isotactic cis-1,4 polymers from various substituted butadienes such as (E)-1,3-pentadiene, (E)-3-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene and 1,3- octadiene, while some nickel and cobalt catalysts (e.g., Ni(acac)2-MAO; Co(acac)3-MAO; CoCl2(PtBu2Me)2-MAO) give highly syndiotactic cis-1,4 polymers from the same monomers. All these highly stereoregular polydienes may also be seen as an inexhaustible and outstanding source of highly stereoregular and perfectly alternating olefin copolymers, hardly obtainable through the simple and common stereospecific copolymerization of the corresponding monomers. Infact, the hydrogenation of isotactic and syndiotactic cis-1,4 polydienes can give perfectly alternating isotactic and syndiotactic ethylene/?-olefin copolymers, as shown in the following scheme. On the synthesis and characterization of isotactic and syndiotactic perfectly alternating ethylene/2- butene2 and ethylene/propylene3 copolymers, we have already reported. In the present communication we describe the synthesis and characterization of i) perfectly alternating ethylene/1-butene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3-hexadiene), iso- and syndiotactic; ii) perfectly alternating ethylene/1-pentene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3-heptadiene), iso- and syndiotactic; iii) perfectly alternating ethylene/1-hexene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3- octadiene), iso- and syndiotactic. 1 G. Ricci, A. Sommazzi, F. Masi, M. Ricci, A. Boglia, G. Leone "Well Defined Transition Metal Complexes with Phosphorus and Nitrogen Ligands for 1,3-Dienes Polymerization" Coord. Chem. Rev. 2010, 254, 661-676. 2 G. Ricci, G. Leone, A. C. Boccia, I. Pierro, G. Zanchin, M. Mauri, M. Scoti, A. Malafronte, F. Auriemma, C. De Rosa "Perfectly alternating ethylene/2-butene copolymers by hydrogenation of highly stereoregular 1,4 poly(1,3-diene)s: synthesis and characterization" Macromolecules 2017, 50, 754-761. 3 G. Ricci, A. C. Boccia, G. Leone, I. Pierro, G. Zanchin, M. Scoti, F. Auriemma, C. De Rosa "Isotactic and Syndiotactic Alternating Ethylene/Propylene Copolymers Obtained Through Non-Catalytic Hydrogenation of Highly Stereoregular cis-1,4 Poly(1,3-diene)s" Molecules 2017, 22, 755.
Perfectly alternating olefin copolymers by hydrogenation of stereoregular cis-1,4 iso- and syndiotactic polydienes
G Ricci;G Leone;I Pierro;G Zanchin;A C Boccia;
2017
Abstract
The stereospecific polymerization of 1,3-dienes with transition metal and lanthanide catalysts can give polymers with different structure (cis-1,4; trans-1,4; 1,2; 3,4; iso- and syndiotactic) from different monomers1. The polymer microstructure mainly depends on the catalyst and monomer structures, and particularly on the combination of these two factors. Thus for instance, the classical ternary system AlEt2Cl/Nd(OCOC7H15)3/Al(iBu)3 gives isotactic cis-1,4 polymers from various substituted butadienes such as (E)-1,3-pentadiene, (E)-3-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-heptadiene and 1,3- octadiene, while some nickel and cobalt catalysts (e.g., Ni(acac)2-MAO; Co(acac)3-MAO; CoCl2(PtBu2Me)2-MAO) give highly syndiotactic cis-1,4 polymers from the same monomers. All these highly stereoregular polydienes may also be seen as an inexhaustible and outstanding source of highly stereoregular and perfectly alternating olefin copolymers, hardly obtainable through the simple and common stereospecific copolymerization of the corresponding monomers. Infact, the hydrogenation of isotactic and syndiotactic cis-1,4 polydienes can give perfectly alternating isotactic and syndiotactic ethylene/?-olefin copolymers, as shown in the following scheme. On the synthesis and characterization of isotactic and syndiotactic perfectly alternating ethylene/2- butene2 and ethylene/propylene3 copolymers, we have already reported. In the present communication we describe the synthesis and characterization of i) perfectly alternating ethylene/1-butene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3-hexadiene), iso- and syndiotactic; ii) perfectly alternating ethylene/1-pentene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3-heptadiene), iso- and syndiotactic; iii) perfectly alternating ethylene/1-hexene copolymers, iso- and syndiotactic, obtained by hydrogenation of cis-1,4 poly(1,3- octadiene), iso- and syndiotactic. 1 G. Ricci, A. Sommazzi, F. Masi, M. Ricci, A. Boglia, G. Leone "Well Defined Transition Metal Complexes with Phosphorus and Nitrogen Ligands for 1,3-Dienes Polymerization" Coord. Chem. Rev. 2010, 254, 661-676. 2 G. Ricci, G. Leone, A. C. Boccia, I. Pierro, G. Zanchin, M. Mauri, M. Scoti, A. Malafronte, F. Auriemma, C. De Rosa "Perfectly alternating ethylene/2-butene copolymers by hydrogenation of highly stereoregular 1,4 poly(1,3-diene)s: synthesis and characterization" Macromolecules 2017, 50, 754-761. 3 G. Ricci, A. C. Boccia, G. Leone, I. Pierro, G. Zanchin, M. Scoti, F. Auriemma, C. De Rosa "Isotactic and Syndiotactic Alternating Ethylene/Propylene Copolymers Obtained Through Non-Catalytic Hydrogenation of Highly Stereoregular cis-1,4 Poly(1,3-diene)s" Molecules 2017, 22, 755.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
