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A Simplified Predictive Tool for Design and Analysis of SET-LRP Reactions with Mechanistic Insight
ACS Applied Polymer Materials ( IF 4.4 ) Pub Date : 2020-10-28 , DOI: 10.1021/acsapm.0c00796
Kevin Gunter 1 , Mirco Sorci 1 , Georges Belfort 1
Affiliation  

Single-electron transfer (SET)-living radical polymerization (LRP) is a robust, fast, “green,” grafting method, similar but different from atom transfer radical polymerization, that operates at ambient temperature in the presence of oxygen and is industrially attractive. Solving a simplified reaction model with only five rather than 12 reactions in solution, for describing the SET-LRP scheme and verifying it with experimental data, we provide (i) a useful tool to predict conversion given initial conditions and rate constants, and (ii) key mechanistic insights with a parametric sensitivity analysis, illustrating the effects of initial conditions, kinetic rate constants, temperature, and copper particle size. Findings include: (i) Increasing the formation rate of radicals (i.e., kact) exhibited a maximum in monomer conversion. (ii) The optimal ratio of initial conditions was found to be [MA]0/[PnX]0/[CuIIX2/L]0 = 222/1/1.5, where [MA]0 = 7.4 M. (iii) Increasing the temperature strongly improved monomer conversion with an inflection point. (iv) Using an order-of-magnitude and Damköhler number analysis, we provide a rationale for selecting small diameter particles and specify how they are likely to perform with SET-LRP reactions. Assumptions of the model include: Solid copper concentration was an infinite source of dissolved CuI and CuII and was available instantaneously (with Damköhler number ≪ 1, for reaction rather than diffusion limitation). Also, the reverse reaction of the disproportionation of CuI was negligible, polymer chain length did not affect reaction kinetics, and all intermediate reactions were neglected.

中文翻译:

具有机理见解的SET-LRP反应设计和分析的简化预测工具

单电子转移(SET)活性自由基聚合(LRP)是一种健壮,快速,“绿色”的接枝方法,与原子转移自由基聚合相似但不同,它在环境温度下,有氧条件下运行,具有工业吸引力。 。为了描述SET-LRP方案并用实验数据进行验证,我们求解了一个简化的反应模型,该模型中只有5个反应而不是12个反应,我们提供了(i)在给定初始条件和速率常数的情况下预测转化的有用工具,以及(ii )通过参数敏感性分析获得的重要机械洞察力,阐明了初始条件,动力学速率常数,温度和铜粒度的影响。研究结果包括:(i)增加自由基的形成率(即k行为)在单体转化率方面显示出最大值。(ii)发现初始条件的最佳比率为[MA] 0 / [P n X] 0 / [Cu II X 2 / L] 0 = 222/1 / 1.5,其中[MA] 0 = 7.4M。 (iii)提高温度极大地改善了具有拐点的单体转化率。(iv)使用量级和Damköhler数分析,我们提供了选择小直径粒子的原理,并指定了它们在SET-LRP反应中可能如何执行。该模型的假设包括:固铜浓度是溶解的Cu I和Cu II的无限来源并可以即时获得(Damköhler≪ 1,用于反应而不是扩散限制)。同样,Cu I歧化的逆反应可以忽略不计,聚合物链长不影响反应动力学,所有中间反应都可以忽略。
更新日期:2020-11-13
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