New Ferroelectric Polymers with Hydrogen Bonding

Hydoegen键的部分具有很大的偶极矩，众所周知，它可以制造有用的聚合物，如尼龙或聚氨酯。预计具有大偶极子的聚合物，如酰胺或氨基甲酸酯基团，将能够通过化学结构的控制具有具有氢键的极性结构。这类聚合物的结构可以是铁电极性聚集体。在这项工作中，我们提出了铁电聚脲、聚酰胺、聚氨酯和聚硫脲，它们具有奇数个CH2基团的线性脂肪链。这些聚合物的化学结构允许在聚合物链和铁电堆积中形成极性结构。因此，首次在脂肪族聚硫脲、聚氨酯和A-B型尼龙中发现了铁电行为。所有聚合物的薄膜几乎都是无定形的，氢键很强。在60ﾟC下测得聚合物的剩余极化为10-100 mC/m~2，热释电常数为5-40 mC/m~2。从氢键的角度讨论了介电、铁电和热释电行为的初步研究。

Hydoegen bonding moieties, which has a large dipole moment, is wellknown to make useful polymers, such as nylons or polyurethanes. It is anticipated that polymers having the large dipoles, like amide or urethane group, would be capable to having a polar structure with hydrogen bonding by the control of chemical structure. The structure of such polymers can be ferroelectric polar aggregates.in this work, we propose ferroelectric polyureas, polyamide, polyurethanes, and polythioureas which have a linear aliphatic chain with odd numbers of CH2 groups. The chemical structure of these polymers permits the formation of a polar structure in the polymer chain and ferroelectric packing.As a result, ferroelectric behavior in aliphatic polythioureas, polyurethanes, and A-B type nylons is found for the first time. The films of all the polymers were almost amorphous with strong hydrogen bonding. The meaasured remanent polarization and pyroelectric onstant in the polymers were found to be 10-100mC/m2 and 5-40mC/m2K at 60ﾟC,respectively. The preliminary studies on dielectric, ferroelectric and pyroelectric behavious was discussed in view of the hydrogen bonding.