Organic Sulfonic Acid Rare Earth Catalyst System Microstructure Controlled Polybutadiene

Nd-polybutadiene is an elastomer with high cis-1,4 content (>94%) and the most linear chain structure (no branching). The polymer, however, has cold-flow due to its linear structure, which causes continued deformation or movement under stress of a load, and thus cold-flow is an important problem in the industry. High trans-1,4 polybutadiene exhibits excellent dynamic properties including good green strength, although, in the past it has attracted less attention from the industrial point of view because of the fact that its high melting temperature (Tm≈150°C) has a negative effect on its processing properties. In this dissertation, in order to improve the mechanical properties of polybutadiene and achieve widespread application, Nd(RSO3)3·nL-AlR3/ AlR2H binary catalyst systems were used to polymerize 1,3-butadiene with controllable cis-1,4 and trans-1,4 chain segments.1. Nd(NO2C6H3SO3Cl)3 compound-alkylaluminium catalysts were used to polymerize 1,3-butadiene. A series of donors contained groups such as C=O, S=O and–OH were used as ligands in Neodymium catalysts. The formed catalysts had good solubility and thermal stability, alkylation reaction completeness. Activated by?different alkylaluminiums, the catalysts actively converted butadiene to cis-1,4 content (51.8%~97.1%, mostly >90%), trans-1,4 content (1.5%~45.2%), yield up to 99.9%. Readily obtained catalyst components and facile catalyst preparation, high activity and stereselectivity as well as mild polymerization conditions suggest that these catalyst systems have potential industry applications.2. A halide-free neodymium m-nitrobenzenesulfonate(Nd(3-NBSA)3) compounds activated by kinds of alkylaluminiums binary catalyst system were prepared. The catalyst system exhibited high activity in butadiene polymerization to produce polybutadiene featuring cis-1,4 content (42.3%~93.9%), trans-1,4 content (4.3%~ 54.3%), Mw (6.0×104~1.5×106g/mol). 13C NMR and DSC analysis demonstrated that polybutadienes obtained had stereo-block chain structures of cis-1,4 and trans-1,4 segments with adjustable Tm, Tc and crystallinity.3. Neodymium benzenesulfonate compounds activated by alkylaluminiums (Nd(C6H5SO3)3·nL)-AlR3/AlR2H catalysts were able to produce polybutadiene with cis-1,4 content (58.7%~97.6%), trans-1.4 content (1.4%~38.0%) at various preparation methods of catalyst and parameters. Polybutadiene with high cis-1,4 content?(94.5%~97.3%) were obtained by adding extra alcohols into Nd(C6H5SO3)3-AlR3 binary catalysts(ROH/Nd(mole ratio)=5), and the polymers were stereo-block chain structures of cis-1,4 and trans-1,4 segments.