PREPARATION OF LONG-BRANCHING POLYETHYLENE USING A DUAL-FUNCTIONAL CATALYTIC SYSTEM

Long branching polyethylene was prepared by using a novel dual functional catalytic system with (acac) 2ZrCl 2/Montmorilonite/AlEt 2Cl as the ethylene oligomerization catalyst in which (acac) 2ZrCl 2 was chemically bonded in between the layers of montmorilonite (MMT) and Et(Ind) 2ZrCl 2/MAO as the ethylene copolymerization catalyst capable of incorporating ethylene oligomers,of which over 80 percent were hexene and octene, in situ to form long branching polyethylene.Selectivities for ethylene oligomerization with (acac) 2ZrCl 2 and (acac) 2ZrCl 2/MMT,relationship between (acac) 2ZrCl 2 and (acac) 2ZrCl 2/MMT with reaction time,effects of Al/Zr value on activity of (acac) 2ZrCl 2/MMT and structure of the resulting polymer were investigated.Experimental results showed that the two catalysts in the dual functional catalytic system were well matched and exhibited high copolymerization activity and improved properties of the final long branching polyethylene.