Thermally Activated One-Pot, Simultaneous Radical and Condensation Reactions Generate Surface-Anchored Network Layers from Common Polymers
Thermally Activated One-Pot, Simultaneous Radical and Condensation Reactions Generate Surface-Anchored Network Layers from Common Polymers
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DOI：
10.1021/acs.macromol.8b02194
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发表时间：
2019-01-22
期刊：
影响因子：
5.5
通讯作者：
Genzer, Jan
中科院分区：
文献类型：
--
作者：
Pandiyarajan, C. K.;Genzer, Jan
我们提出了一种通用的一锅合成方法，通过使用热活性6-叠氮磺酰基己基三乙氧基硅烷（6-ASHTES），它作为交联剂和表面锚定剂的交联常见的聚合物，产生表面附着的聚合物网络。我们在衬底上存款一层包含给定量6-ASHTES和聚合物的混合物薄层（类似于200 nm），并在高温（100-140摄氏度）下对其进行退火。在加热时，磺酰叠氮基团释放氮，并且所得氮烯从聚合物中的相邻C-H键中夺取质子，并经历C-H插入反应和/或重组以形成磺酰胺键。在本体连接6-ASHTES单元中的乙氧基硅烷头基之间的缩合完成交联。同时，6-ASHTES与底物结合的-OH或C-H基团反应，并将共价交联的聚合物连接到底物上。我们进行了系统的研究凝胶动力学，包括退火温度，退火时间，和各种聚合物系统的6-ASHTES的浓度。这种简单而通用的方法涉及同时进行的自由基和缩合反应，可调节聚合物网络中的凝胶分数，并将网络锚定到各种基材上。
We present a versatile one-pot synthesis method that generates surface-attached polymer networks by cross-linking common polymers using thermally active 6-azidosulfonylhexyltriethoxysilane (6-ASHTES), which acts as a cross-linker and a surface-anchoring agent. We deposit a thin layer (similar to 200 nm) of a mixture comprising a given amount of 6-ASHTES and a polymer onto the substrate and anneal it at elevated temperatures (100-140 degrees C). Upon heating, the sulfonyl azide groups release nitrogen, and the resulting nitrenes abstract protons from the neighboring C-H bonds in polymers and undergo a C-H insertion reaction and/or recombination to form sulfonamide bonds. Condensation among ethoxysilane headgroups in bulk links 6-ASHTES units completes cross-linking. Simultaneously, 6-ASHTES reacts with substrate-bound -OH or C-H groups and attaches the covalently cross linked polymer to the substrate. We carry out systematic investigation of gel kinetics involving annealing temperature, annealing time, and the concentration of 6-ASHTES for various polymer systems. This simple yet versatile approach involving simultaneous radical and condensation reactions adjusts the gel fraction in the polymer network and anchors the network to various substrates.