ISSN 1070-4272, Russian Journal of Applied Chemistry, 2015, Vol. 88, No. 10, pp. 1723−1727. © Pleiades Publishing, Ltd., 2015.
Synthesis of a Novel Titanium Complex Catalyst
and Its Catalytic Performance for Oleﬁ n Polymerization
, Yajiao Wang
, Yanliu Dang
, Qingze Jiao
, Qin Wu
, and Yun Zhao
School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing, 100081 China
School of Chemical Engineering and Material Science, Beijing Institute of Technology, Zhuhai, 519085 China
Received October 16, 2015
Abstract—A phenoxy-ester Ti based complex of bis[5-methyl-3-trimethylsilyl phenyl salicylate]titanium(IV)
dichloride was prepared for oleﬁ n polymerization. The structures of the ligand and the complex were characterized
using infrared spectrometer, nuclear magnetic resonance, and mass spectrum. The novel [O,O]bidentate coor-
dination compound was used as the catalyst for ethylene and propylene polymerization together with i-Bu
as the cocatalyst in toluene. It was found that the as-prepared catalyst displayed activity for both
polymerization and copolymerization. As-obtained ethylene propylene copolymer was random copolymer. The
glass transition temperature of the copolymer was −43.3°C.
The text was submitted by the authors in English.
Po lyoleﬁ n is recognized as the most in ﬂ uential
industry to the national economy and people’s livelihood
of the 20th century due to their notable properties; for
example, they are lightweight and possess excellent
mechanical strength, ﬂ exibility, processability, and
chemical inertness. It is no surprise that polyoleﬁ n
are widely used in agriculture, packaging, electronics,
electrical engineering, automobile industry, machinery,
and daily groceries. The key of polyoleﬁ n technology is
the development of catalysts for polymerization.
The discovery of Ziegler−Natta catalysts in the
1950s launched the production of polyethylene and
polypropylene . However, they do not exhibit good
copolymerization performance. Metallocene catalysts
possess a well-deﬁ ned active site, and can contribute to
the narrow molecular weight distribution of polyoleﬁ n.
In addition, metallocene catalysts provide us systematic
chances to study the mechanisms of coordination
polymerization and stereoselective polymerization,
which has signiﬁ cantly contributed to advance in
the design of catalysts for controlled oleﬁ n (co)-
polymerization. Therefore, lots of groups show great
interests in the research of new single site catalysts.
As a result of the huge amount of research, a large
number of new high-activity single site catalysts based
on a wide array of early and late transition metals have
been discovered [2−5]. On this basis, Fujita with his
group discovered that salicylaldimine could serve as
excellent ligands for oleﬁ n polymerization catalysts
with early transition metals  (phenoxy-imine
compounds, namely FI catalysts). FI catal yst, with the
special electronic and steric effects, shows excellent
performance. Therefore the polymer molecular weight,
molecular weight distribution, comonomer composition,
and polymer stereoregularity can be precisely controlled
by the structure of ligands and/or catalysts.
Based on the new concept of “ligand-oriented
catalyst design” [7, 8], we design phenoxy–ester ligated
titanium catalyst for oleﬁ n (co)polymerization . In
this work, the ligand was prepared by introduction of
substituents with space steric hindrance and electronic
effect to phenoxy-ester (a kind of electron donor) matrix.