Polyimides fluorinated

Ren and co-workers [31] investigated the thermal stability of the fluorinated polyimide, by Py-MS and Fourier-transform infrared spectroscopy. 

TGA carried out at 590 °C, 670 °C and 740 °C showed that this compound gave two peaks, the first of which at 485-621 °C was associated with fluorine and is associated with the production of HCF and trifluorotoluene (C H CFj). 

Matsuda and Ando [34] discuss the control of molecular orientation and anisotropic optical properties of uniaxially drawn fluorinated PI films based on pyromellitic dianhydride and 2,2 - fs-(trifluoromethyl)-4,4 -diaminobiphenyl used for light wave circuit applications. Methods of controlling in-plane birefringence in PI films were developed and a PI waveplate was prepared. This waveplate was inserted into a groove formed in an arrayed waveguide grating, the polarisation dependence of which was completely eliminated. 

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Often the substitution of fluorine atoms for hydrogen atoms in a polymer chain markedly increases the thermal stabiUty of the base polymer this is tme for polyimides. A typical fluorinated polyimide is prepared from the reaction of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and 2,2-bis-(4-amino phenyl)hexafluoropropane according to the following reaction (36) ... 

Ha et al. demonstrated that dispersed TPD in a fluorine-containing polyimide matrix as a HTM has significantly improved device performance (Scheme 3.17) [91]. Flexible and fluorinated polyimide as a matrix exhibits the lowest turn-on voltage and a high EL efficiency [92]. 

Fluorinated olefins, 77 866 Fluorinated organics, production of, 77 847 Fluorinated polyimides, 20 278 Fluorinated thermoplastics, 10 8 Fluorinated titanocycle, 25 118 Fluorinating agents, electrophilic, 77 847 Fluorination, 9 281, 678-679 aromatic ring, 77 866 chlorocarbons, 6 235 direct, 77 864, 882 electrochemical, 77 864—865, 882 of germanium, 72 552 halogen exchange, 77 861-864 selective, 77 831... 

Pechar, T.W., Tspatsis, M., Marand, E., and Davis, R. (2002) Preparation and characterization of a glassy fluorinated polyimide zeolite mixed matrix membrane. Desalination, 146, 3-9. 

The primary purpose of incorporating fluorine into polyimide structures is to decrease the dielectric constant. Considerable effort has been devoted to the creation of new chemistry and to understanding the limits and principles behind this approach. 12.25-27,29,31-34,51-60,65,78,158 ygjygg gf (jjg dielectric constant in nonfluorinated polyimides generally range from about 3.0 to 4.0. Fluorinated polyimides generally range from about 2.6 to 3.3 (see Table 13.3). 

Mercer et al. have studied the effect of moisture in fluorinated polyimides extensively. Beuhler et al. have also studied moisture absorption in fluorinated polyimides and have shown that moisture absorption decreases with fluorine incorporation, even as free volume increases (see Table 13.6). 

Recently, much progress has been made in fine-tuning the properties of fluorinated polyimides by copolymerization. Serious property conflicts, such as the countertrends of the desirable decrease in dielectric constant with fluorine incorporation and the undesirable increase in CTE have been significantly resolved by judicious choice of comonomers and their ratios. 

Fluorinated polyimides have been made with a broad range of chemical structures and possess an equally wide range of properties. Their value as low-dielectric, hydrophobic, and thermally stable materials is now well established in industry, and work continues to try to further understand underlying principles of structure-property relationships. 

Optical Transparency of Fluorinated Polyimides at Near-IR Wavelengths... 

These characteristics show that perfluorinated polyimides are promising materials for waveguides in integrated optics and optical interconnect technology. The thermal, mechanical, and optical properties of perfluorinated polyimides can be controlled by copolymerization in the same manner as partially fluorinated polyimides. ... 

Synthesis and Properties of Partially Fluorinated Polyimides for Optical Applications... 

Stability for use in optical interconnects. In the near future, optoelectronic integrated circuits and optoelectronic multichip modules will be produced. Materials with high thermal stability will thus become very important in providing compatibility with conventional 1C fabrication processes and in ensuring device reliability. Polyimides have excellent thermal stability so they are often used as electronic materials. Furuya et al. introduced polyimide as an optical interconnect material for the first time. Reuter et al. have applied polyimides to optical interconnects and have evaluated the fluorinated polyimides prepared from 6FDA and three diamines, ODA (3), 2,2-bis(3-aminophenyl) hexafluoropropane (3,3 -6F) (4), and 4,4 -6F (2), as optical waveguide materials. 

This chapter describes the synthesis of partially fluorinated polyimides for optical teleconununications applications," " 2 their optical transparency (optical loss), refractive index, and birefringence properties" in addition to their fundamental properties. It also describes their device application as optical interference filters," " optical waveplates," and optical waveguides." -" ... 

The dielectric constant of dry (0%RH atmosphere) 6FDA/TFDB is as low as 2.8 because of its four trifluoromethyl groups (fluorine content 31.3%). The low dielectric constant of fluorinated polyimides results from the low electronic polarizability of fluorine-containing groups and the reduced chain-chain elec-... 

Rigid-Rod Fluorinated Polyimides PMDA/TFDB, P2FDA/TFDB, P3FDA/TFDB, and P6FDA/TFDB... 

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