Polyimides 7: Synthesis, characterization, and properties of novel soluble semifluorinated poly(ether imide)s

Abstract

Three novel diamine monomers (VI, VII, and VIII) were synthesized. These diamine monomers lead to a number of semifluorinated poly(ether imide)s when reacted with different commercially available dianhydrides like pyromellitic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropene (6FDA), and oxydiphthalic dianhydride (ODA) by thermal imidization route. Elemental analyses, IR and NMR techniques were used to characterize the monomers and polymers. The resulting polymers exhibited weight average molar masses up to 1.78 Â 10 5 g mol À1in GPC with respect to polystyrene standard and have very good solubility in several organic solvents such as NMP, DMF, DMAC, DMSO, chloroform, and THF. Very good solubility of these polymers in CDCl 3 enables their complete characterization by proton as well as 13 C-NMR techniques. The polymers showed very high thermal stability with decomposition temperature (5% weight loss) up to 5118C in air and high glass transition temperature up to 3118C depending upon the exact repeating unit structure. The polymer films showed high modulus (up to 2.9 GPa) as was evaluated by DMA. The polymers also showed very low water absorption (0.16%), low dielectric constant (2.35 at 1 MHz) and very good optical transmission.

Synthesis and properties of organosoluble polyimides based on novel perfluorinated monomer hexafluoro-2,4-toluenediamine

“…ODPA-based PI-2 has a lower T g value than 6FDA-based PI-1 (328 vs. 346 8E) due to the presence of a flexible ether linkage in the PI backbone. The same T g s ratio was reported for PIs prepared from these dianhydrides and various diamines [25][26][27][28].…”

“…Temperatures of 5 and 10% weight losses of ODPA-based PI-2 exceed the same characteristics of 6FDA-based PI-1 by 20-30 8E both in inert and oxidative atmosphere. This tendency for T d changes is known to realize for pair of ODPA/6FDA-based PIs prepared using various diamines [25,[27][28][29]; it is caused by a lower thermal stability of the 6F linkage as compared with the oxygen linkage.…”

Novel flame retardant poly(thiourea-sulfone-imide)s for high temperature applications: synthesis and characterization

“…The inherent viscosities were found to be in the range of 0.89-1.13 dL/g, indicating the formation of medium to high molecular weight polymers. 37,38 As expected, SPT-6FDA having a hexafluoroisopropylidene group displayed the lowest η inh among all the polyimides. This is because the presence of these bulky groups in the polymer backbone hinders the close packing of the polymer chain.…”

Synthesis and characterization of fluorinated polyimides derived from 1,4-bis-[4-amino-2-(trifluoromethyl)-phenoxy] benzene/tetrafluoride benzene

“…[12] In addition, introducing flexible functional groups especially the -CF 3 and -C(CF 3 ) 2 − to the polymer backbones can significantly enhance moisture uptakes and optical properties of the PIs. [13][14][15][16][17][18][19][20][21] At the same time, the existence of bulky substituent moieties could increase the free volume and decrease the dielectric constants and water absorptions. And the PIs derived from 9,9-bis [4-(4-amino-2-trifluoromethyl-phenoxy) phenyl] xanthene [22] and 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl [23] confirmed it.…”