| abstract |
The invention provides a composition used for a rare earth catalyst. The composition contains alkyl aluminum and/or alkyl aluminum hydride, a rare earth compound and conjugated diene. The rare earth compound is a compound having a general formula as MR3.nL, wherein M is a rare earth metal, R is halogen, L is an electron-donating ligand, and the value of n is 1-3. Also, the alkyl aluminum and/or alkyl aluminum hydride, the rare earth compound and the conjugated diene are in a molar ratio of 0.05-1.5:0.01-0.05:1. The invention provides a rare earth catalyst, which is obtained by enabling the composition provided in the invention to contact an inert organic solvent mutually under the protection of an inert gas. Specifically, the contact condition enables the conjugated diene in the composition to polymerize so as to obtain a conjugated diene polymer with a polymerization degree of not less than 150. The invention also provides application of the catalyst in the polymerization of conjugated diene. The rare earth catalyst provided in the invention has good stability, and is in favor of synthesizing polymer products with stable quality and uniformity when it is used for conjugated diene polymerization. |