Compounded Interplay of Kinetic and Thermodynamic Control over Comonomer Sequences by Lewis Pair Polymerization
Compounded Interplay of Kinetic and Thermodynamic Control over Comonomer Sequences by Lewis Pair Polymerization
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DOI：
10.1021/jacs.2c10568
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发表时间：
2022-12-15
影响因子：
15
通讯作者：
Chen，Eugene Y-X
中科院分区：
文献类型：
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作者：
Reilly，Liam T.;McGraw，Michael L.;Chen，Eugene Y-X
设计一锅共聚物直接聚合生成明确嵌段共聚物（bcp）的简便合成路线，而不是传统的顺序添加，从根本上和技术上都很重要。这种合成方法通常利用相对的单体反应性来繁殖物种，因此在单体范围和对共聚物结构的控制方面相当有限。Lewis对聚合（LPP）复合序列控制（CSC）利用热力学（Keq）和动力学（kp）分化的协同作用，精确控制BCP序列，抑制逐渐变细和误结合误差。在这里，我们通过LPP对CSC进行了深入的研究，重点关注了基本的keqandkpparameters的复杂相互作用，这使得CSC-LPP能够精确控制各种极性乙烯基单体类的共聚单体序列。对一系列商业相关单体的路易斯酸平衡和聚合速率参数进行了实验量化、计算验证和合理化。这些值允许明智地设计共聚，探索关于在共单体混合物的CSC-LPP过程中出现的keqandkpbias之间关系的建设性与冲突性质的多种假设。这些关系被深入探讨，并与所得共聚物的微观结构直接相关。介绍了几个高阶bcp的例子，进一步展示了该方法提供的材料创新潜力。
The design of facile synthetic routes to well-defined block copolymers (BCPs) from direct polymerization of one-pot comonomer mixtures, rather than traditional sequential additions, is both fundamentally and technologically important. Such synthetic methodologies often leverage relative monomer reactivity toward propagating species exclusively and therefore are rather limited in monomer scope and control over copolymer structure. The recently developed compounded sequence control (CSC) by Lewis pair polymerization (LPP) utilizes synergistically both thermodynamic (Keq) and kinetic (kp) differentiation to precisely control BCP sequences and suppress tapering and misincorporation errors. Here, we present an in-depth study of CSC by LPP, focusing on the complex interplay of the fundamentalKeqandkpparameters, which enable the unique ability of CSC-LPP to precisely control comonomer sequences across a variety of polar vinyl monomer classes. Individual Lewis acid equilibrium and polymerization rate parameters of a range of commercially relevant monomers were experimentally quantified, computationally validated, and rationalized. These values allowed for the judicious design of copolymerizations which probed multiple hypotheses regarding the constructive vs conflicting nature of the relationship betweenKeqandkpbiases, which arise during CSC-LPP of comonomer mixtures. These relationships were thoroughly explored and directly correlated with resultant copolymer microstructures. Several examples of higher-order BCPs are presented, further demonstrating the potential for materials innovation offered by this methodology.