Modification of the Acyl Chloride Quench-Labeling Method for Counting Active Sites in Catalytic Olefin Polymerization

The reliable and efficient counting of active sites in catalytic olefin polymerization has been realized by using acyl chloride as the quench-labeling agent. However, molar ratio to alkylaluminum cocatalyst must be larger than 1 order completely depress side reactions between quencher Al-polymeryl that is formed via chain transfer reaction. In this work, a tetrahydrofuran/thiophene-2-carbonyl (THF/TPCC) mixture was used quenching agent when propylene catalyzed MgCl2/Di/TiCl4 (Di = internal electron donor)-type Ziegler–Natta catalyst activated with triethylaluminum (TEA). When THF/TEA TPCC/TEA smaller 1, [S]/[Ti] polymer quenched THF/TPCC same only TPCC at > indicating all bearing propagation chain. replacement part THF did not influence precision site method, but it effectively reduced amount chloride. This modification method significantly precious brought benefit simplifying purification procedures after step.