| 摘要 |
Rubbery polybutadiene is prepared by means of a catalyst comprising MAIH4 (M = Na, K, Rb, Cs and preferably Li) and TiCl4, and preferably AlCl3; the MAIH4 is preferably used with a solvent (particularly an ether), and an inert diluent (e.g. benzene, toluene, xylene, ethylbenzene and paraffin with up to 10 carbon atoms) is preferably used in polymerisation. Preferred conditions are (a) 0 DEG -150 DEG C. and pressure sufficiently to maintain the reaction mixture in the liquid phase; (b) ageing the catalyst in mid diluent before use, at about 30 DEG -100 DEG C for 10 minutes-24 hours; (c) isolating the polymer by means of an alcohol, particularly isopropyl alcohol; (d) using an antioxidant, e.g. phenylbetanaphthylamine during isolation. The proportions of 1:2-, cis-1:4- and trans-1:4-structures in the polybutadiene are noted. The products are blended and cured according to a conventional rubber compounding recipe. The following applications are mentioned :-tyres, gaskets, tubing, heels, tile and covering for wire and cable. Specification 776,326 also is referred to.ALSO:A catalyst for polymerizing butadiene comprises (a) MAlH4 wherein M is Na, K, Rb, Cs or preferably Li and (b) TiCl4. Additionally, AlCl3 may be used as a catalyst constituent. Preferably, (1) use is made of an inert diluent in mixing the constituents and in subsequent polymerization e.g. benzene, toluene, xylene, ethylbenzene and paraffins with up to 10 carbon atoms; (2) the MAlH4 is added to a solvent before use, e.g. dialkyl ethers such as diethyl ether and cyclic ethers such as dioxane and tetrahydrofuran; (3) the catalyst is aged before use at about 30-100 DEG C. for 10 minutes24 hours. Specification 776,326 also is referred to.
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