| 摘要 |
A method of polymerizing unsaturated hydrocarbons in which the hydrocarbon is contacted with a catalyst in a reaction zone and a coolant is passed in indirect heat exchange with the reaction mixture in the zone comprises measuring the volume or flow rate of coolant vapours evaporated as a result of the indirect heat exchange and adjusting the rate of introduction of catalyst or hydrocarbon into the reaction zone so as to maintain a predetermined coolant evaporation rate and recovering an efficient stress containing polymer. Specified hydrocarbons are ethylene, propylene, isobutene, butadiene and styrene alone or in admixture with one another. The preferred catalyst is chromium oxide associated with at least one of the amides of silica, alumina, zirconia, and thoria. The coolant is preferably circulated in indirect heat exchange at a constant rate and under constant pressure, preferably being at boiling temperature when passed into the indirect heat exchange. Apparatus for carrying out the process is described. Specifications 790,195 and 804,641 are referred to.
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