Characterization of MgCl2/Alcohol Based Ziegler−Natta Catalyst and its Precursors
MgCl2/alcohol complex treated with various Al-alkyl in preparing Ziegler-Natta catalyst and its precursors for polymerization of ethylene have been studied by XPS, SEM, and EDS. With different treatments, their different morphology and various structures were discussed in details. As a result, Al-alkyl treatment for MgCl2/alcohol complex plays a dominant role in dispersing active titanium on surface of catalyst. The proper species and concentration of Al-alkyl were confirmed to have high performance in dispersing titanium species in treatment of MgCl2/ alcohol complex. With lower concentration of TEA treatment, Ti distribution in catalyst was even with surface and body Ti/Mg ratio 0.04 and 0.03 respectively. In comparison, with higher concentration of TEA treatment, more Ti would be loaded on surface of catalyst. Ti distribution became to be uneven to form clubbed crystals on the surface. EDS results showed that Ti/Mg ratio was up to 6.2 on the clubbed crystals.
Zhong Cao, Lixian Sun, Xueqiang Cao, Yinghe He
W. Q. Huang et al., "Characterization of MgCl2/Alcohol Based Ziegler−Natta Catalyst and its Precursors", Advanced Materials Research, Vols. 233-235, pp. 1568-1574, 2011