| 摘要 |
Propylene is polymerized in the presence of a catalyst consisting of a freshly exposed surface of a finely divided metal selected from titanium, zirconium, hafnium, vanadium, niobium, or tantalum, with (a) a halogen or a hydrogen halide, or (b) with a tri- or tetrahalide of the above mentioned metals, or (c) with a hydride of a metal of titanium, zirconium, or hafnium, in the presence of a hydrogen halide. The polymerization may be effected in bulk or in the presence of an inert hydrocarbon diluent such as hexane, heptane, benzene, toluene, xylene, or chlorobenzene. The finely divided metal, e.g. from 1 micron to about 100, may be obtained by ball milling in an inert atmosphere, atomising molten metal, for by reducing a metal oxide with hydrogen. The hydride may be preformed, or formed in situ by reacting the metal with hydrogen. The polymer may be purified by leaching with n-butanol and aqueous hydrogen fluoride.
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