Synthesis and properties of new polyimides containing flourinated alkoxy side chains

Aromatic polyetherimides were synthesized from a fluorine containing aromatic carboxylic acid dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride (6F-BABPA) and five typical aromatic diamines including 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (3F-DAM) by two-step procedures-amidation to polyamic acids (PAA), followed by thermal imidization of PAA. The chemical and physical properties of the newly prepared polyetherimides (PEI) were compared in terms of their chemical structures, inherent viscosities, mechanical, and thermal properties. All polyetherimides were well soluble in common organic solvents such as N-methyl-2-pyrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), pyridine, and methylene chloride. A PEI prepared from 6F-BABPA/3F-DAM was especially easily dissolved in NMP. The glass transition temperature (T g ) range of the obtained PEI was 209 -257°C. The dielectric constants and refractive index were 2.8 -3.2 and 1.61-1.56, respectively. The polyetherimide, 6F-BABPA/BAPP, with a low fluorine content (11.4% fluorine content), has 0.99% water absorption, whereas the polyetherimide, 6F-BABPA/4-BDAP, having a high fluorine content (26.0% fluorine content) showed 0.35% of water absorption.

Section: Soluble Aromatic Polyetherimidesmentioning

confidence: 79%

Section: Soluble Aromatic Polyetherimidesmentioning

confidence: 79%

“…The chemical structure of prepared 6F-BABPA was confirmed by its IR, 1 H-, 13 C-NMR, elemental analysis, and melting (Figs. 1-4).…”

Section: Soluble Aromatic Polyetherimidesmentioning

confidence: 91%

Section: Measurementsmentioning

confidence: 99%

“…1 H-NMR and 13 C-NMR studies were performed on a Varian Unity plus 300 NMR (300 MHz) and a Bruker Avance Digital 400 NMR (400 MHz) spectrometer with chemical shifts reported in ppm.…”

Section: Measurementsmentioning

confidence: 99%

See 3 more Smart Citations

Preparation and properties of soluble aromatic polyetherimides based on 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride

Lee

Koo

Kim

et al. 2000

Synthesis and properties of flourine-containing polyimides

Wang

Yang

1997

A series of new fluorine-containing polyimides have been synthesized from the condensation of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl] -1,1,1,3,3,3 -hexafluoropropane, or 2,2 -bis[4 -(4 -amino -2 -trifluoromethylphenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane with various aromatic dianhydrides. The dielectric constant at 1 KHz in the fluorine-containing polyimides decreases from 3.51 to 2.72 as fluorine content increases. The poly(amic acid)s had inherent viscosities of 0.52-1.23 dL/g, depending on the diamines and dianhydrides. Most of the resulting polymers showed an amorphous nature and afforded flexible and tough films. The amount of moisture absorption decreases as fluorine content in polyimides increases. The glass transition temperatures of these polyimides were in the range of 287-328ЊC, and the 10% weight loss temperatures were above 542ЊC in nitrogen.

Preparation and properties of novel fluorinated polyimides based on 2,2?,6,6?-tetrafluorobenzidine

Yin

et al. 1998

Fluorinated polyimides were prepared from 2,2Ј,6,6Ј-tetrafluorobenzidine and four conventional dianhydride monomers by a solution polycondensation reaction followed by a chemical imidization. Polyimide based on 2,2Ј,6,6Ј-tetrafluorobenzidine and hexafluoroisopropylidene bis(3,4-phthalic anhydride) (6FDA) is soluble in organic solvents such as NMP, DMA, DMF, THF, chloroform, and acetone while those based on 2,2Ј,6,6Ј-tetrafluorobenzidine and pyromellitic dianhydride (PMDA), benzophenone-3,3Ј,4,4Ј-tetracarboxylic acid dianhydride (BTDA), diphenylether-3,3Ј,4,4Ј-tetracarboxylic acid dianhydride (ETDA) are not. Polyimide from 2,2Ј,6,6Ј-tetrafluorobenzidine and 6FDA possesses high optical transparency at 350 -700 nm and has a in-plane refractive index of 1.558 at 632.8 nm. All polyimides exhibit glass transition temperatures above 350°C. They also possess very high thermal stability.