| 摘要 |
The present invention refers to homogeneous polymerization of styrene and acrylic monomers (for instance methyl methacrylate) using as catalysts, ytterbiocene bimetallic complexes (ytterbium in oxidation level 2) and aluminum hydrides, which have as general formula, Cp*2YbA1H3L. Cp* ligands are substituted cyclopentadienyls (C5RnH5-n) or substituted indenyls (c9RnH7-n) which form ytterbium complexes (Yb) of good solubility (for instance, Di-tert-butylcyclopentadienyl). L ligand can be triethylamine, tetrahydrofurane or ethylic ether. R can be any alkyl or aryl substitute o a combination of both. Subindex "n" may have values from 1 to 7. The use of the referred catalyst for styrene polymerization results in polymers having a molecular weight of up to 2x10 to the 5th power and a molecular weight distribution between 1.50 and 2.05. The use of the referred catalysts for acrylic monomers polymerization results in polymers having a molecular weight of up to 1x10 to the 6th power and a molecular weight distribution between 1.34 and 2.15. After toluene precipitation in methanol, powdered white colored polymers are obtained.
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