As is known, the polymerization of 1,3 butadiene in the presence of Ziegler type titanium containing catalytic systems based on tetravalent titanium mostly yields cis 1,4 polybutadiene.The catalytic systems of tri and divalent titanium (α , γ , or δ ), TiCl 3 /R 3 Al possess the trans regulat ing ability in the polymerization of butadiene [2]. The polymerization of butadiene catalyzed by the system TiX 4 /organomagnesium compound/Al(i C 4 H 9 ) 3 (X = Cl, I) gives rise to polybutadiene containing 90-95% trans 1,4 units [3].For polymerization of conjugated dienes [4][5][6][7][8][9], the stereoregulation and activity of catalytic systems and the molecular mass distribution and microstructure of polydienes are substantially affected by such parame ters as the nature and valence state of a transition metal (titanium, vanadium), the catalyst concentra tion, the nature of an organoaluminum compound, the type of modifying additives, the polymerization temperature, the nature of the support (MgCl 2 , SiO 2 ) , and the homogenization or heterogenization of the catalytic system [4][5][6][7][8][9].On the basis of the published data, the authors of review [6] arrived at the conclusion that titanium con taining Ziegler systems cannot be regarded as promis ing for the trans polymerization of butadiene and 1 This work was supported by the Russian Foundation for BasicResearch, project no. 09 03 00231 a. † Deceased. other dienes in terms of their stereospecificity and activity. In summary, they mentioned that the situa tion changes when titanium containing catalysts sup ported on the surface of solid supports (MgCl 2 , SiO 2 ) are used.A series of studies was devoted to the polymeriza tion of 1,3 dienes and characterization of the resulting polymers [10][11][12][13][14][15]. It was shown that the polymeriza tion of both butadiene and isoprene occurs in the pres ence of silica gel supported titanium-magnesium catalysts (TMCs) combined with Al(i C 4 H 9 ) 3 and TMCs modified with organometallic compounds of Ni or Zr to produce polydienes containing 80-98% trans 1,4 units.The advancement of studies in the field of design ing stereospecific and highly active TMCs enabled the authors of [16-20] to develop a new family of TMCs, titanium-magnesium nanocatalysts (TMNCs), which are suitable for the trans polymerization of con jugated dienes (butadiene, isoprene) [21][22][23][24], ethyl ene polymerization that yield ultrahigh molecular weight PE, and the polymerization of α olefins (pro pylene, 3 methyl 1 butene) [25][26][27].The aim of this study is to investigate the polymer ization of 1,3 butadiene in the presence of TMNCs and to characterize the trans 1,4 polybutadiene (TPB) being synthesized.Abstract-The suspension polymerization of butadiene in the presence of titanium-magnesium nanocata lysts combined with triisobutylaluminum is studied. The resulting polybutadiene is shown to contain up to 99% trans 1,4 units. The dependences of polymer microstructure on temperature and the Al to Ti ratio are investigated. The kinetic parameters of...
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