Among odd‐nylons, nylon‐5 exhibits the highest remanent polarization and is thus a desirable material for many applications of ferroelectric polymers. However, nylon‐5 has never been used as a ferroelectric material, because the synthesis of nylon‐5 and its processing into thin films are challenging. This work revisits the synthesis of nylon‐5 via anionic ring opening polymerization (AROP) and studies the effect of reaction time and scale‐up on (i) molecular weight (M_n), (ii) melting point (T_m), (iii) yield, and (iv) ferroelectric properties. For the first time, the molecular weight of nylon‐5 is characterized via size exclusion chromatography (SEC), nuclear magnetic resonance (NMR) spectroscopy, as well as matrix assisted laser desorption ionization time of flight mass spectroscopy (MALDI ToF‐MS), showing M_n values of up to 12 500 g mol^‐1. Extended reaction times and the synthesis on a larger scale increase the molecular weight and yield. Nylon‐5 thin films are fabricated from a TFA:acetone (60:40 mol%) solvent mixture. Nylon‐5 thin‐film capacitors are ferroelectric and show a remanent polarization as high as 12.5 ± 0.5 μC cm^‐2, which is stable in time. The high remanent polarization values, combined with the facile solution processing, render nylon‐5 a promising candidate for future microelectronic and multi‐ferroic applications.

中文翻译：

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尼龙5铁电薄膜的合成和溶液处理：奇尼龙的复兴？

在奇数尼龙中，尼龙5表现出最高的剩余极化率，因此是铁电聚合物许多应用中理想的材料。但是，尼龙5从未用作铁电材料，因为尼龙5的合成及其加工成薄膜具有挑战性。这项工作重新探讨了通过阴离子开环聚合（AROP）合成尼龙5的方法，并研究了反应时间和放大倍数对（i）分子量（M _n），（ii）熔点（T _{m）的影响}），（iii）产量和（iv）铁电特性。尼龙5的分子量首次通过尺寸排阻色谱（SEC），核磁共振（NMR）光谱以及基质辅助激光解吸电离飞行时间质谱（MALDI ToF-MS）进行了表征，显示的M _n值高达12 500 g mol ^-1。延长反应时间和大规模合成可增加分子量和收率。尼龙5薄膜是由TFA：丙酮（60:40 mol％）混合溶剂制成的。尼龙5薄膜电容器是铁电的，并显示出高达12.5±0.5μCcm ^-2的剩余极化，时间稳定。高残留极化值，加上简便的溶液处理，使尼龙5成为未来微电子和多铁性应用的有希望的候选者。