Exploring the Effects of Bulky Cations Tethered to Semicrystalline Polymers: The Case of Tetraaminophosphoniums with Ring-Opened Polynorbornenes
Exploring the Effects of Bulky Cations Tethered to Semicrystalline Polymers: The Case of Tetraaminophosphoniums with Ring-Opened Polynorbornenes
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DOI：
10.1021/acs.macromol.0c00422
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发表时间：
2020-10-13
期刊：
影响因子：
5.5
通讯作者：
Noonan, Kevin J. T.
中科院分区：
文献类型：
--
作者：
Treichel, Megan;Womble, C. Tyler;Noonan, Kevin J. T.
在此，开发了一种简单的合成方法，用碱稳定的四氨基膦阳离子在S-位上官能化藜芦烯。在确认阳离子单体可以以活性方式聚合后，以异丙烯为共聚单体合成了统计和二嵌段共聚物。氢化后，统计共聚物是有效的阴离子交换材料，而二嵌段没有产生独立的膜。差示扫描量热法和原子力显微镜表明，结晶度主要是抑制由庞大的磷阳离子的统计共聚物，与影响有点依赖于结合到磷原子的氨基。小角X-射线散射曲线显示了一个两相形态与3纳米的领域所产生的离子簇在膜中。总而言之，该研究揭示了这些新型鏻阳离子对聚合物组织和填充的巨大影响，这是在阴离子传输材料中靶向较大离域阳离子时的关键考虑因素。
Herein, a simple synthetic method to functionalize norbornene at the S-position with a base-stable tetraaminophosphonium cation was developed. Upon confirmation that the cationic monomer could be polymerized in a living fashion, statistical and diblock copolymers were synthesized with norbornene as a comonomer. After hydrogenation, the statistical copolymers were effective anion-exchange materials, while the diblock did not produce a free-standing film. Differential scanning calorimetry and atomic force microscopy indicated that crystallinity was mostly suppressed by the bulky phosphonium cations in the statistical copolymers, with the impact somewhat dependent on the amino groups bound to the phosphorus atom. Small-angle X-ray scattering profiles revealed a two-phase morphology with 3 nm domains arising from ion clustering in the film. Altogether, the study revealed the large impact these novel phosphonium cations have on polymer organization and packing, which is a critical consideration when targeting larger delocalized cations in anion-transport materials.