| 摘要 |
High molecular weight non-halogenated and/or non-sulphohalogenated polymers of mono- and/or di-olefins are isolated in a granular and uniform state, from viscous solutions of the polymers in organic solvents which are immiscible with water, by mechanically fragmenting and subdividing the solutions in water which is in a state of turbulent motion, and at a temperature above the boiling point of the organic solvent, or the water/solvent azeotropic mixture, maintaining the polymer particles in a state of turbulent motion until the solvent evaporates, cooling the aqueous suspension, and separating the polymer particles. The polymers may be made by use Ziegler-type catalysts, or free-radical catalysts such as benzoyl peroxide, azoisobutyric acid dinitrile, diacetyl peroxide. potassium persulphate, or hydrogen peroxide, Solvents mentioned are butane, pentane, hexane, heptane, cyclohexane, methyl-cyclohexane, tetrahydronaphthalene, decahydronaphthalene, benzene, toluene, xylene, ethylbenzene, mixtures of hydrocarbons having a boiling range of 60 to 250 DEG C., carbon tetrachloride, 1:2-dichloroethane, and chlorobenzene. The mechanical fragmenting is preferably effected with a stirrer having multi-sharp-edged blades, and operating at a speed of 300 to 3,000 revolutions per minute. Turbulent flow is created by injecting steam or air into the mixture of the organic solvent solution and hot water. The polymers may be copolymers or homopolymers of ethylene, propylene, butylene, butadiene, 2-chlorobutadiene, 2-methyl-butadiene, or styrene, for example polybutadiene, a copolymer of butadiene and styrene, and a copolymer of butadiene and acrylonitrile. In the examples is described (1) the recovery of a copolymer of ethylene and propylene made by using a catalyst consisting of vanadium isobutylester and Al(C2H5)2Cl, from a 10% solution in toluene, and (2) the recovery of polyisoprene in small granules having a diameter of 5-8 mms, from a solution in gasoline of polyisoprene made by polymerization in the presence of a catalyst consisting of TiCl4 and Al(C2H5)3. Specification 418,069 and U.S.A. Specification 2,592,814 are referred to. |
