Synthesis and properties of fluorinated polyimides. 1. Derived from novel 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl

Abstract

A new diamine monomer, 4,4″‐bis(aminophenoxy)‐3,3″‐trifluoromethyl terphenyl (ATFT) was synthesized that led to a number of novel fluorinated polyimides by solution as well as thermal imidization routes when reacted with different commercially available dianhydrides like pyromellatic dianhydride (PMDA), benzophenone tetracarboxylic acid dianhydride (BTDA), or 2,2‐bis(3,4‐dicarboxyphenyl) hexafluoropropane (6FDA). The polyimides ATFT/BTDA and ATFT/6FDA derived from both routes were soluble in several organic solvents such as N,N‐dimethylformamide, N,N‐dimethylacetamide, and dimethyl sulfoxide. The polyimide ATFT/PMDA was only soluble in N‐methylpyrollidone. The polyimide films had low water absorption of 0.3–0.7%, low dielectric constants of 2.72–3.3 at 1 Hz, refractive indices of 1.594–1.647 at 589.3 nm, and optical transparency >85%. These polyimides showed very high thermal stability with decomposition temperatures (5% weight loss) up to 532 °C in air and good isothermal stability; only 7% weight loss occurred at 400 °C after 7 h, and less than 0.6% weight loss was observed at 315 °C for 5 h. Transparent thin films of these polyimides exhibited tensile strengths up to 112 MPa, a modulus of elasticity up to 3.05 GPa, and elongation at break up to 21% depending on the repeating unit structure. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1016–1027, 2002

Organosoluble, thermally stable and low dielectric constant fluorinated polyimides containing 2,4,5-triphenylimidazole moiety in the main chains

“…Recent studies demonstrated that polyimides derived from ether-bridged aromatic diamines with trifluoromethyl (-CF 3 ) groups are soluble high-temperature polymeric materials with low-moisture uptake, low dielectric constant, high optical transparency and low birefringence. [22][23][24][25][26][27][28][29] Imidazole ring is a useful n-type building block with high-electron affinity and good thermal stability and has been successfully incorporated in small molecules and polymers as the electron-transport component of OLEDs.…”

Polyimides. IV. Synthesis and characterization of fluorinated copolyimides

“…The solubility behavior of these copolyimides did not show significant improvements in comparison to their homopolymer analogs. 6 This was possibly due to the formation of random copolyimide structures. Park et al 24 observed drastic differences in solubility between alternating copolyimides and their corresponding random isomers.…”

“…5 Thus, the polyimides based on trifluoromethyl groups have been reported to be soluble in amide, ketones, and chlorinated hydrocarbons. 6,7 Other means of solubilization of polyimides includes the introduction of flexible linkages, 8,9 bulky substituents, 10,11 or bulky units in the polymer backbone [12][13][14] or noncoplanar 15,16 or alycyclic 17 monomers. ODA is widely used in the synthesis of polyimides, but the polyimides synthesized from this diamine are insoluble or have poor solubility, depending on the dianhydride used.…”

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

“…Recently, it had also been proved that polyimide contained the trifluoromethyl or ether group can enhance the solubility and thermal stability, reduce dielectric constant and moisture absorption, and raise the optical transparency. [18][19][20][21][22] In this study, the bis(ether anhydride) I was prepared and a series of novel poly(ether imide)s (III) were prepared from I with CF 3 -contained diamines II a{g . These polymers were investigated in regard to their solubility, color, optical transparency, dielectric property, and moisture absorption, and they were compared to analogous non-fluorinated poly(ether imide)s IV.…”