Flame‐resistance of polyetherimides

Abstract

Polyetherimides containing isopropylidene and hexafluoroisopropylidene groupings were obtained by the interaction of m‐phenylenediamine with the dianhydrides of 2, 2‐bis[4‐(3, 4‐dicarboxyphenoxy) phenyl]‐propane and 2, 2‐bis[4‐(3, 4‐dicarboxyphenoxy) phenyl] hexafluoropropane using high‐temperature solution polycyclocondensation in phenolic solvents. The same procedure was used for the preparation of the isopropylidene‐ and hexafluoroisopropylidene‐containing polyetherimides on the basis of 3, 3′ 4, 4′‐tetracarboxy(diphenyl ether) dianhydride and 2, 2‐bis[4‐(3‐aminopheno‐xy)phenyl] hexafluoropropane. Investigation of the polymers obtained has demonstrated that the replacement of isopropylidene groupings for hexafluoroisopropylidene fragments in polyetherimides leads to the increasing of the polymers flame‐resistance.

Synthesis and Structure‐Property Relationships of Fluorinated Poly(ether imide)s as Electret Materials

“…2a :10 Yield 93%. IR (KBr): 1 781 (imide I), 1 726 (imide II), 1 604, 1 510, 1 479, 1 445, 1 359 (CN stretching), 1 262, 1 240 (aryl ether stretching), 1 174, 1 104, 1 018, 968, 928, 849, 775, 744 (CN bending), 707, 683, 626 cm −1 .…”

“…Krause et al reported that commercial PEIs (Ultem®) have charge storage potential 8. Since it is crucial for electret materials to be good insulators, fluorinated PEIs9, 10 are promising candidates for electret materials; for instance, this class of polymers was investigated as high temperature low‐k polymers 11–14. However, to our knowledge, fluorinated PEIs have not yet been investigated as electret material.…”

Condensation monomers and polymers based on 2,4,6-trinitrotoluene

“…After addition of toluene to the reaction mixture (for azeotropic distillation of water), the reaction temperature is raised to 180 AE 10 8C and the solution is kept at this temperature for 6 AE 1 h. This method has recently found wide acceptance in PI synthesis. 95,126 Cyclisation of PCA 30a ± d and 31a ± d from all the aromatic tetracarboxylic dianhydrides 2a ± d occurs under homogeneous conditions and yields PI 32a ± d and 33a ± d with moderate viscosities (Z red = 0.28 ± 0.80 dl g 71 ) and high degrees of cyclisation.…”

“…The PI 17 ± 21 can be prepared by three routes: 95 (1) lowtemperature polycondensation in N-MP with subsequent catalytic imidisation of the PCA formed in the reaction solution in the presence of pyridine ± acetic anhydride (1 : 1); (2) high-temperature polycondensation in N-MP in the presence of azeotropeforming compounds; (3) high-temperature polycondensation in m-cresol catalysed by isoquinoline.…”