Copolymerization of Propylene and Polar Monomers by a New Ziegler-Natta Catalyst System with Diether as Internal Donor

Synthesis of Polar-functionalized Isotactic Polypropylenes Using Commercial Heterogeneous Ziegler–Natta Catalyst

“…These results indicated that the ICS effectively addresses the issue of rapid deactivation of Ziegler−Natta catalysts in olefinpolar monomer copolymerization. 33 As the partial pressure of propylene increased, the copolymerization activity (∼1.1 × 10 7 g mol −1 h −1 ) and molecular weight of the copolymer increased, while the incorporation ratio of polar monomers decreased (Table 1, entries 10,13,14). An increase in polar monomer concentration led to a decrease in activity and molecular weight, along with an increased comonomer incorporation ratio (Table 1, entries 1,9, and 15).…”

“…It should be noted that the “ionic cluster strategy” is conceptually different from the conventional “masking agent strategy”. The masking strategy requires that the amount of aluminum cocatalyst (masking regent) is larger than that of polar monomer (Al/polar monomer >1), and the polymerization activity increases with the increasing amount of aluminum regent. ,,,,,,, The ionic cluster strategy requires that the amount of aluminum cocatalyst is smaller than that of polar monomer (Al/polar monomer <1), and the polymerization activity increases with the decreasing amount of aluminum regent (Figure A) …”

“…The masking strategy requires that the amount of aluminum cocatalyst (masking regent) is larger than that of polar monomer (Al/polar monomer >1), and the polymerization activity increases with the increasing amount of aluminum regent. 1,4,8,14,23,33,34,45 The ionic cluster strategy requires that the amount of aluminum cocatalyst is smaller than that of polar monomer (Al/polar monomer <1), and the polymerization activity increases with the decreasing amount of aluminum regent (Figure 1A). 35 The ionic cluster strategy greatly reduces the increased cost due to the use of excess organoaluminum reagents, which is of great significance to the cost-sensitive polyolefin industry.…”

“…Despite some recent academic advancements, the focus has remained on homogeneous catalytic systems (Scheme B), ,,− which are challenging to commercialize due to issues like reactor fouling. , However, more than 99% of industrial iPP production employs heterogeneous Ziegler–Natta catalysts, − which enable continuous production and better operability via excellent product morphology control. − However, heterogeneous Zielger–Natta catalysts have long been overlooked in the field of olefin-polar monomer copolymerization for an extended period. Some early studies have shown that this catalyst exhibited very low activities in propylene-polar monomer copolymerization, even in the presence of a large excess amount of alkylaluminum masking agent. ,,,,,, Therefore, the development of a process for the utilization of commercially available Ziegler–Natta catalysts for efficient propylene-polar monomer copolymerization could represent a breakthrough in this field. Such a development would provide a “drop-in” technology that could greatly facilitate the practical implementation of this process and eventually enable the industrial production of polar-functionalized iPP via copolymerization.…”

“…Some early studies have shown that this catalyst exhibited very low activities in propylene-polar monomer copolymerization, even in the presence of a large excess amount of alkylaluminum masking agent. 1,4,8,14,23,33,34 Therefore, the development of a process for the utilization of commercially available Ziegler−Natta catalysts for efficient propylene-polar monomer copolymerization could represent a breakthrough in this field. Such a development would provide a "drop-in" technology 1 that could greatly facilitate the practical implementation of this process and eventually enable the industrial production of polarfunctionalized iPP via copolymerization.…”