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How the catalyst circulates and works in organocatalyzed atom transfer radical polymerization
AIChE Journal ( IF 3.5 ) Pub Date : 2018-03-10 , DOI: 10.1002/aic.16134
Jun‐Kang Guo 1 , Zheng‐Hong Luo 1
Affiliation  

The catalyst plays a vital role in organocatalyzed atom transfer radical polymerization (O‐ATRP). Catalysts in the ground‐state, excited‐state, and oxidized‐state are in competitive equilibrium and mutually transforming status. However, the catalyst circulation process remains unclear in some respects. In this work, for the first time, a novel kinetic model is successfully developed to illustrate the exact circulation process and working mechanism of catalyst. For a broad range of conditions, the reported model presents excellent descriptions of kinetic behaviors of O‐ATRP. In the polymerization process, the photolysis effect contributes to a small proportion of radical generation. Sufficient deactivation effect is crucial for controlled polymerization at the early stage of polymerization. And increased light intensity, halide ion concentration, catalyst loading and initiator concentration accelerate the establishment of catalyst dynamic equilibrium. Additionally, the excited‐state catalyst quenches with an extremely high rate, leading to an immediate dormant period in “on–off” light switching regulation. The formulated results shed light on the catalyst circulation process and provide insights into the polymerization kinetics. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2581–2591, 2018

中文翻译:

催化剂如何在有机催化的原子转移自由基聚合中循环和工作

催化剂在有机催化的原子转移自由基聚合(O-ATRP)中起着至关重要的作用。基态,激发态和氧化态的催化剂处于竞争平衡和相互转化的状态。然而,催化剂循环过程在某些方面仍不清楚。在这项工作中,首次成功地开发了新的动力学模型,以说明催化剂的精确循环过程和工作机理。对于各种条件,报告的模型都很好地描述了O-ATRP的动力学行为。在聚合过程中,光解作用有助于小部分自由基的产生。足够的失活作用对于聚合反应初期的受控聚合至关重要。并增加了光强度,卤离子浓度,催化剂的负载和引发剂的浓度加快了催化剂动态平衡的建立。此外,激发态催化剂以极高的速率淬灭,导致“开-关”光开关调节立即进入休眠期。配制的结果阐明了催化剂的循环过程,并为聚合动力学提供了见识。©2018美国化学工程师学会AIChE J,64:2581–2591,2018
更新日期:2018-03-10
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