| 摘要 |
<p>BUTADIENE POLYMERISATION PROCESS Catalytic polymerisation of butadiene to cis-1,4-polybutadiene, conducted in the absence or substantial absence of solvents or diluents. . According to said process, a catalytic mixture is prepared by bringing into contact, in a hydrocarbon vehicle, one or more neodymium compounds, one or more halogen contributor compounds, one or more compounds containing hydroxyls, and an aluminium organometal and/or hydride compound. Said catalytic mixture is brought into contact with liquid butadiene monomer, and the resultant mixture is fed continuously to one end of an elongated plug-flow polymerisation reactor in which the butadiene is polymerised. Alternatively, said polymerisation reactor is fed continuously with a stream of the catalytic mixture and a stream of liquid butadiene. The heat of polymerisation is removed by partial evaporation of the butadiene monomer, so that by controlling the pressure of this latter it is possible to maintain the polymerisation temperature within the predetermined range. By also controlling the catalyst composition, the butadiene monomer/catalyst ratio, the polymerisation temperature and the residence time in the reactor, it is possible to produce mixtures containing from about 25% to about 70% of polymer by weight, which are discharged continuously from the other end of the polymerisation reactor. The cis-1,4-polybutadiene is recovered as final product from the discharged mixture by evaporating the unreacted butadiene and any solvent used as the catalyst vehicle from the polymer mass, to which a short stopper for the catalyst and stabilisers against thermooxidative degradation have been added. This evaporation takes place in an extruder-desolventiser.</p> |
