One kind of polyethylene composition and preparation and application

The present invention relates to a high-density polyethylene composition and its preparation and application; magnesium dichloride dissolved isooctanol, decane, reaction with titanium tetrachloride, a reaction temperature of -10 ℃ ~ -18 ℃, chloroformate substituting cyclohexane, maintaining -18 ℃ 1 h, heated 3 hours to 110 deg.] C, the silane was added, the precipitate was dried to obtain a catalyst; agent was added to the aluminum alkyl co-catalyst for the polymerization of ethylene; polymerization temperature was raised to 50 ℃, into ethylene and hydrogen, hydrogen / ethylene volume ratio of 4.5 to 7.5; 80-86 deg.] C reaction temperature, reaction pressure 0.6Mpa-1.0Mpa; discharged unreacted hydrogen, ethylene was added comonomer CnH2n, 0 600%.