| 摘要 |
Polythenes are prepared by subjecting oxygen-free ethylene (containing less than 1000 part per million of oxygen) to elevated temperature and pressure in the presence of a normally liquid non - polymerizable organic medium and an organo-lithium compound. The temperature may range from 25 DEG to 350 DEG C., and the preferred range of pressure is 20-1500 atmospheres. The solvent medium is generally a saturated aliphatic or aromatic hydrocarbon such as benzene, iso-octane, toluene or petroleum ether, but diethyl ether may be used in some cases. While any organo-lithium compound may be used, the preferred classes are the alkyl-lithiums and the aryl-lithiums, such as methyl-lithium, n-butyl-lithium, isoamyl-lithium, octyl-lithium, dodecyl-lithium, phenyl-lithium and benzyl - lithium. Specifications 471,590, 536,102 and 8070/40 (as open to inspection under Sect. 91) are referred to.
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