Sukhanova Tatyana E, Didenko Andrey L, Borisov Ilya L, Anokhina Tatyana S, Ivanov Aleksey G, Nesterova Anna S, Kobykhno Ilya A, Yushkin Alexey A, Kudryavtsev Vladimir V, Volkov Alexey V
S.V. Lebedev Institute of Synthetic Rubber, Gapsal'skaya ul. 1, 198035 St. Petersburg, Russia.
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, 29 Leninsky Prospekt, 119991 Moscow, Russia.
Membranes (Basel). 2022 Dec 7;12(12):1235. doi: 10.3390/membranes12121235.
Poly-(4,4'-oxydiphenylene) pyromellitimide or Kapton is the most widely available polyimide with high chemical and thermal stability. It has great prospects for use as a membrane material for filtering organic media due to its complete insolubility. However, the formation of membranes based on it, at the moment, is an unsolved problem. The study corresponds to the rediscovery of poly(4,4'-oxydiphenylene-pyromellitimide)-based soluble copoly(urethane-imides) as membrane polymers of a new generation. It is shown that the physical structure of PUI films prepared by the solution method becomes porous after the removal of urethane blocks from the polymer, and the pore size varies depending on the conditions of thermolysis and subsequent hydrolysis of the membrane polymer. The film annealed at 170 °C with a low destruction degree of polycaprolactam blocks exhibits the properties of a nanofiltration membrane. It is stable in the aprotic solvent DMF and has a Remasol Brilliant Blue R retention coefficient of 95%. After the hydrolysis of thermally treated films in acidic media, ultrafiltration size 66-82 nm pores appear, which leads to an increase in the permeate flow by more than two orders of magnitude. This circumstance provides opportunities for controlling the membrane polymer structure for further optimization of the performance characteristics of filtration membranes based on it. Thus, we proposed a new preparation method of ultra- and nanofiltration membranes based on poly(4,4'-oxydiphenylene-pyromellitimide) that are stable in aprotic solvents.
聚（4,4'-氧二亚苯基）均苯四酸二酰亚胺或聚酰亚胺薄膜 Kapton 是最常见的具有高化学和热稳定性的聚酰亚胺。由于其完全不溶性，它作为过滤有机介质的膜材料具有很大的应用前景。然而，目前基于它制备膜仍然是一个未解决的问题。该研究相当于重新发现了基于聚（4,4'-氧二亚苯基-均苯四酸二酰亚胺）的可溶性共聚（聚氨酯-酰亚胺）作为新一代膜聚合物。结果表明，通过溶液法制备的 PUI 薄膜在从聚合物中去除聚氨酯嵌段后，物理结构变得多孔，并且孔径根据膜聚合物的热解和随后水解的条件而变化。在 170°C 退火且聚己内酰胺嵌段破坏程度较低的薄膜表现出纳滤膜的性能。它在非质子溶剂 DMF 中稳定，雷马素亮蓝 R 的截留系数为 95%。在酸性介质中对热处理后的薄膜进行水解后，会出现尺寸为 66 - 82 nm 的超滤孔，这导致渗透通量增加两个以上数量级。这种情况为控制膜聚合物结构以进一步优化基于它的过滤膜的性能特征提供了机会。因此，我们提出了一种基于聚（4,4'-氧二亚苯基-均苯四酸二酰亚胺）的在非质子溶剂中稳定存在的超滤和纳滤膜的新制备方法。
