Kinetics of Polymer Interfacial Reactions: Polymer Brush Formation by Click Reactions of Alkyne End-Functional Polymers with Azide-Functional Substrates
Kinetics of Polymer Interfacial Reactions: Polymer Brush Formation by Click Reactions of Alkyne End-Functional Polymers with Azide-Functional Substrates
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DOI：
10.1021/acs.macromol.6b01220
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发表时间：
2016-07
期刊：
影响因子：
5.5
通讯作者：
Shuo Zhang;T. Vi;Kai Luo;J. Koberstein
中科院分区：
文献类型：
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作者：
Shuo Zhang;T. Vi;Kai Luo;J. Koberstein
用衰减全反射红外光谱(ATR-IR)直接测定了在DMF溶剂中，铜催化的端炔基聚苯乙烯与聚丙烯酸丁酯和叠氮功能底物之间的1，3-偶极环加成反应速率。观察到四个行为区域：最初，反应速率是扩散控制的t1/2标度；在链重叠开始的交叉区，速率与ln(T)成比例关系；然后，速率短暂加速；最后，在末端或渗透受限区域，面密度的对数与时间成线性关系。扩散受限、交叉和渗透受限区域的动力学行为很好地符合Ligoure和Leibler的预测。斑点模型表明，速度的加快是由于蘑菇到灌木丛转变过程中的侧链收缩。提出了预测饱和度面密度为Σ饱和度∼MW-1.2时，才能较好地解决该问题的理论。
Attenuated total reflectance infrared spectroscopy (ATR-IR) is used to directly measure the rates of copper-catalyzed 1,3-dipolar cycloaddition reactions between alkyne-terminated polystyrene and poly(n-butyl acrylate) and azide-functional substrates in the good solvent DMF. Four regimes of behavior are observed: initially, the reaction rate is diffusion-controlled scaling with t1/2; in the crossover regime at the onset of chain overlap, the rate scales with ln(t); the rate then accelerates briefly; and finally, in the terminal or penetration-limited regime, the logarithm of areal density scales linearly with time. Kinetic behavior in the diffusion-limited, crossover, and penetration-limited regimes corresponds well to the predictions of Ligoure and Leibler. The blob model suggests that the acceleration in rate is due to lateral chain contraction during the mushroom to brush transition. A theory is presented to predict that the areal density at saturation should scale as Σsaturation ∼ Mw–1.2 for good solv...