Effect of Borate Co‐Catalyst on Ethylene‐Propylene Binary/Ternary Copoly‐Merization with Bisindenyl Zirconocene

ABSTRACT Background The choice of co‐catalyst significantly impacts metallocene catalyzed ethylene propylene copolymerization. This study compares methylaluminoxane (MAO) and borate/TIBA systems for efficiency and comonomer incorporation. Objective Copolymerizations were catalyzed by Me 2 Si(Ind) 2 ZrCl 2 activated with MAO (Al/Zr = 2500) or borate/TIBA (B/Zr = 1.5). Activities were measured at varying E/P ratios (4/6 to 8/2) and 5‐ethylidene‐2‐norbornene (ENB) concentrations. Results The MAO system achieved peak activity (6.89 × 10 6 g·mol −1 ·h −1 ) at E/P = 4/6, while borate/TIBA reached 6.76 × 10 6 g·mol −1 ·h −1 (E/P = 8/2). Terpolymerization with ENB showed 180% higher incorporation (6.97%) using borate, with equivalent activity (2.87 × 10 6 g·mol −1 ·h −1 ) and molecular weight to MAO. Conclusion Borate/TIBA reduces co‐catalyst loading (B/Zr = 1.5 vs. Al/Zr = 2500) while maintaining performance, offering a cost‐effective alternative for industrial EPM/EPDM production.