Hydrothermal Synthesis of Composition- and Morphology-Tunable Polyimide-Based Microparticles

Abstract

Polyimide is one of the most important high-performance polymers, which is widely used due to its excellent mechanical performance and thermal stability. Unlike the conventional synthetic approach, hydrothermal polymerization enables the synthesis of polyimides without any toxic solvent and catalyst. Herein, we report the synthesis of polyimide-based microparticles (PIMs) through one-pot hydrothermal polymerization using precursors of mellitic acid (MA) and three isomers of phenylenediamine (PDA) (o-, m-, and p-PDA). Interestingly, the chemical composition of PIMs was highly tunable with the choice of the PDA isomers, leading to considerable morphological differences between PIMs. The molecular dynamics simulation and density functional theory calculation of the polymeric segment of the respective PIMs suggested that the relative ratio of amide to imide influenced the rotational freedom of the polymeric chains and number of hydrogen bonds, resulting in the well-defined structures of respective PIMs. Considering the highly tunable nature of PIMs coupled with the facile synthetic protocol, we anticipate prospective potentials of PIMs in materials, energy, and composite applications.

Hydrothermal Generation of Conjugated Polymers Using the Example of Pyrrone Polymers and Polybenzimidazoles

“…[1][2][3] However,ithas just been in recent years that they were also successfully applied to generate an umber of advanced organic highperformance polymers.T od ate,o nly two classes of macromolecular compounds,t hat is,v arious polyimides (PIs) and polyamides (PAs), have successfully been generated hydro-thermally. [4][5][6][7][8] TheH Tp reparation of these polymers is characterized by experimental simplicity as well as inherent environmental friendliness and low cost, since neither sophisticated synthetic skills nor toxic solvents nor harmful catalysts are needed. In hydrothermal polymerization (HTP), H 2 Oisnot only the sole solvent and catalyst, it is also the only reaction byproduct formed (PIs and PA sa re condensation polymers).…”

“…aniline), a cyclic imide moiety is formed via cyclocondensation (Scheme A top) . Generally, the HT formation of imides has already been extensively investigated: Both small molecules and a multitude of different PIs can be efficiently synthesized. In the example introduced above, the formed imide moieties are cyclic and six‐membered.…”

Hydrothermal polymerization of porous aromatic polyimide networks and machine learning-assisted computational morphology evolution interpretation

“…Only one publication has targeted the preparation of amorphous polymer networks by HTP, specically a poly(amide imide) network, using mellitic (benzenehexacarboxylic acid; here each pair of adjacent CO 2 H groups is required per intended imide linkage) in combination with different aromatic diamines. However, the reported product is not a fully condensed network or framework, but rather consists of oligomers that can only be converted to a network-type higher molecular weight species by thermal annealing through solid-state postcondenzation at 340 C. 32 With this contribution, we have set out to, for the rst time, hydrothermally prepare highly condensed aromatic PI networks. We chose the comonomers 1,3,5-tris(4-aminophenyl)benzene (TAPB) and pyromellitic acid (PMA) to synthesize the network PI(TAPB-PMA), see Fig.…”

Hydrothermale Synthese von konjugierten Polymeren am Beispiel von Pyrronpolymeren und Polybenzimidazolen

“…Erst in den letzten Jahren wurden HT‐Methoden auch erfolgreich zur Herstellung einer Reihe von anspruchsvollen organischen Hochleistungspolymeren eingesetzt. Bisher wurden jedoch nur zwei Klassen von makromolekularen Verbindungen erfolgreich hydrothermal gewonnen, nämlich verschiedene Polyimide (polyimides, PIs) und Polyamide (polyamides, PAs) . Die HT‐Herstellung dieser Polymere zeichnet sich durch experimentelle Einfachheit sowie inhärente Umweltfreundlichkeit und geringe Kosten aus, da weder ausgeprägte synthetische Fähigkeiten noch toxische Lösungsmittel oder schädliche Katalysatoren benötigt werden.…”

“…B. Anilin) umsetzt, wird über eine Zyklokondensation ein zyklisches Imid gebildet (Schema A, oben) . Im Allgemeinen wurden HT‐Imidbildungen bereits ausführlich untersucht: Sowohl kleine Moleküle als auch eine Vielzahl verschiedener PIs konnten auf effiziente Weise synthetisiert werden. In dem gerade vorgestellten Beispiel sind die gebildeten Imidgruppen zyklisch und sechsgliedrig.…”