On-Demand Transformation of Carbon Dioxide into Polymers Enabled by Comb Shaped Metallic Oligomer Catalyst

Quantitative transformation of CO2 can greatly elevate the sustainability impact of CO2 chemical utilization, but it is formidably challenging due to the sluggish kinetics requiring overwhelmingly excess usage of CO2. Here, we report an on demand CO2 transformation by a switch polymerization method, that is, all reactants including CO2 are fully converted without any by-product, generating tailor-made poly(ether carbonate) polyols (CO2-polyols) whose composition and chain length exactly correspond to the feed of CO2, epoxide and diacid. This is the first time for CO2 as a countable monomer which is in most cases obscurely considered as “pressure condition”. Studies on the kinetics rate law and the activation parameters of key intermediates disclose that it is the multisite cooperativity from metallic oligomer catalyst that facilitates quantitative insertion of CO2 into polymer backbone without adverse backbiting throughout the polymerization. Hence, this work not only introduces the conception of quantitative CO2 transformation, but engineers exquisite CO2-based polymer which is rarely achieved.