| 摘要 |
Oxidized ethylene polymers are produced by oxidizing polyethylene and ethylene/butene-1 copolymers of melt index less than 0.01 by mixing the polymer in solid form with 0.01-5.0% of an organic peroxide capable of generating free radicals at 80-140 DEG C. and heating the mixture in the presence of free oxygen while maintaining the polymer at at least 80 DEG C. and below the melting point of the polymer until the carbonyl content is at least 0.05% and the ratio of this to the square root of the melt index is above 0.08. The organic peroxide, e.g. 0.1-1%, may be a perester, e.g. t-butyl perbenzoate, or a true peroxide, e.g. benzoyl or dicumyl peroxide. The heating may be effected in a fluidized bed, forced air oven or rotating drum. The peroxide may be added to the polymer in solution in a hydrocarbon, e.g. benzene, which is evaporated off before the oxidation. The polymer may be in particulate form. An anti-oxidant, e.g. 4,41-thiobis-(6-t-butylmetacresol), may be added to the oxidized polymer. The oxidized polymer may be cross-linked, e.g. by milling, with aluminium isopropoxide. Specification 971,998 is referred to. |
