High-Pressure Synthesis of Aliphatic Polyimides via Salt Monomers Composed of Aliphatic Diamines and Oxydiphthalic Acid

Abstract

Aliphatic polyimides having inherent viscosities of 0.4-2.8 dL g1 were readily synthesized by the melt or solid-state polycondensation under high pressure of the salt monomers composed of aliphatic diamines having 6-12 methylene chains and 4,4'-oxydiphthalic acid at 140-330 O C under 250-650 MPa. It is notable that the high-pressure polycondensation proceeded rapidly with the elimination of water in the closed reaction vessel and was almost complete within 3 h. The polyimides having six and eight methylene units were highly crystalline yellowish white solids, whereas those with odd number carbons were amorphous pale yellow resinous products. The thermal behavior of the polyimides are also discussed.

High-pressure synthesis of aliphatic polypyromellitimides via nylon-salt-type monomers composed of aliphatic diamines and pyromellitic acid diesters

“…7,9,10,12 This was also the present case for the high-pressure thermal polycondensation of the salt monomers 12mPME and 12PME, giving polyimide P-12PM, and of a series of the salt monomers XPME producing P-XPM as well. Figure 1 shows the temperature dependence of inherent viscosity of the polyimides prepared by the highpressure polycondensation of the two isomeric salt monomers 12mPME and 12PME for 15 h. Both of the salt monomers gave quite similar pattern of the polymerization curves by the polycondensation under a pressure of 450 MPa (curves A and B).…”

“…Although the endothermic peak temperatures of the salt monomers XPME, which correspond to the imideforming reaction temperatures as reported previously, [7][8][9][10][11][12] were some 50 -90°C lower than those of the parent salt monomers XPMA, the melting temperatures (T m ) of polyimides P-XPM from the salt monomers XPME agreed very closely with those of the polymers from the parent salts XPMA, as summarized in Table I. 11 Since both of the aliphatic polypyromellitimides prepared by the high-pressure polycondensation were inherently high crystalline nature, no glass transition temperatures were detected on the DSC traces.…”

“…1,5,6 Recently we reinvestigated this kind of salt monomer method and found that the nylon-salt-type monomers were extremely reactive, producing directly polyimides by the polycondensation even under high pressure in a very short reaction time at a temperature around 250°C . [7][8][9][10][11][12][13] The present study has two objectives. The one is to compare the polymer-forming reactivity of the two isomeric nylon-salt-type monomers derived from both pyromellitic acid m-and p-substituted diethyl esters with dodecamethylenediamine, and the properties of the two resultant polyimides with each other (Scheme 1).…”

Photoconductivity of a Polyimide with an Alicyclic Diamine Doped with N,N,N′N′-Tetramethyl-p-phenylenediamine

“…13 -15 and Itoya et a/. 16 have reported that the polyimides prepared from alicyclic or aliphatic diamines are attracting much interest because they have good optical, photochemical and dielectric properties as well as good thermal stability. One of the reasons for their high performance is due to the elimination of charge transfer, because the charge transfer state of aromatic polyimides is formed between aromatic diamines as electron donors and aromatic dianhydrides as electron acceptors both intra-and intermolecularly.…”

High-pressure synthesis and properties of aliphatic-aromatic polyimides via nylon-salt-type monomers derived from aliphatic diamines and benzophenonetetracarboxylic acid

“…High-pressure diamine-based polyimides (hereafter referred as aliphatic polyimides). [4][5][6][7] Edwards and Robinson 8 synthesis of the polyaddition-type aromatic polymers such as polyoxadiazole, 10 polyaminoimide, 11 first described the synthesis of aliphatic polyimides in 1955 by the melt polycondensation of the nylonpolycyanurates, 12 polydiazetidinediones, 13 and polyisocyanurates 14 have been studied in our laborasalt-type monomers derived from aliphatic diamines and aromatic tetracarboxylic acids or their tory. Three decades ago, Morgan and Scott 15,16 reported the high-pressure polycondensation of the diester acids.…”