A High Throughput Experimentation Protocol for Quantitative Measurements of Regioselectivity in Ziegler-Natta Polypropylene Catalysis

This paper introduces a High Throughput Experimentation method for fast and accurate evaluations of regioselectivity in Ziegler-Natta (ZN) propene polymerizations. With a simple protocol, the (very low) fraction of regioirregular 2,1 monomeric units in the polymers can be quantitated by means of 13C NMR chain-end analyses on single H2-terminated polypropylene samples. The method, that was successfully validated for three representative ZN catalyst systems, also provides information on catalyst ‘dormancy’ and propensity to undergo chain hydrogenolysis. This opens the door to the rapid and accurate implementation of Quantitative Structure-Activity Relationship (QSAR) databases of regioselectivity and ‘hydrogen response’ in this important industrial catalysis.