Synthesis and properties of flourine-containing polyimides

Abstract

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.

Organo-soluble and Lightly-colored Fluorinated Polyimides Based on 2,2-Bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane Dianhydride and Aromatic Bis(ether amine)s Bearing Pendent Trifluoromethyl Groups

“…2,2-Bis(4-hydroxyphenyl)hexafluoropropane (6F-bisphenol-A; Acros), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (mp 132-133 C, II a ), 24 1,2-bis(4-amino-2-trifluoromethylphenoxy)benzene (mp 116-117 C, II b ), 25 4,4 0 -bis(4-amino-2-trifluoromethylphenoxy)biphenyl (mp 155-156 C, II c ), 12 4,4 0 -bis(4-amino-2-trifluoromethylphenoxy)-3,3 0 ,5,5 0 -tetramethylbiphenyl (mp 256-257 C, II d ), 26 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]propane (mp 131-132 C, II e ), 27 2,2-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane (mp 65-66 C, II f ), 28 9,9-bis[4-(4-amino-2-trifluoromethylphenoxy)-phenyl]fluorene (mp 239-240 C, II g ), 29 4,4 0 -bis(4-aminophenoxy)biphenyl (mp 137-138 C, II f , Chriskev) were used as received. Commerially available aromatic dianhydrides including PMDA (Lancaster), BTDA (Acros), and ODPA (Chriskev) were recrystallized from acetic anhydride before use.…”

“…9,10 Among the six kinds of commercially available aromatic dianhydrides including pyromellitic dianhydride (PMDA), 3,3 0 ,4,4 0 -benzophenone-tetracarboxylic dianhydride (BTDA), 3,3 0 ,4,4 0 -biphenyltetracarboxylic dianhydride (BPDA), diphenylsulfone-3,3 0 ,4,4 0 -tetracarboxylic dianhydride (DSDA), 4,4 0 -oxydiphthalic dianhydride (ODPA) and 6FDA, the polyimides were deriving from ODPA or 6FDA with aromatic diamines showed lighter color than others. The reason was proposed that polyimides containing ether chains [11][12][13] or hexafluoroisopropylidene group 9,14 could reduce the CTC formation of polymer. Therefore, we synthesized the bis(ether anhydride) containing ether chains and hexafluoroisopropylidene group, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (I), and produced a series of lightly-colored poly(ether imide) films with various aromatic diamines.…”

Organosoluble and Light-Colored Fluorinated Polyimides Based on 1,2-Bis(4-amino-2-trifluoromethylphenoxy)benzene and Aromatic Dianhydrides

“…12 Fluorination is also known to enhance the solubility and optical transparency of polyimides. [13][14][15] Therefore, it is expected that fluorinated polyimides will be widely applied in electro-optical and semiconductor industries.…”

“…12 Fluorination is also known to enhance the solubility and optical transparency of polyimides. [13][14][15] Therefore, it is expected that fluorinated polyimides will be widely applied in electro-optical and semiconductor industries.Recent studies demonstrated that polyimides derived from ether-bridged aromatic diamines with trifluoromethyl (3F) groups, such as 1,3-or 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, are soluble and high temperature polymer materials with low dielectric constant, high optical transparency, † To whom correspondence should be addressed. and low birefringence.…”

Light-Color Soluble Polyimides Based on α,α′-Bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1,3-diisopropylbenzene and Aromatic Dianhydrides

“…13 Fluorination is also known to enhance the solubility and optical transparency and to lower moisture absorption of polyimides. [14][15][16] Therefore, it is expected that fluorinated polyimides will be widely applied in electro-optical or semiconductor industries. Recent studies have demonstrated that polyimides derived from ether-bridged aromatic diamines with a trifluoromethyl (3F) group are generally soluble with low moisture uptakes, low dielectric constants, high optical transparency, and low birefringence.…”