Optical properties of polyimides

Along with their excellent high temperature stability, polyimides also possess remarkable electrical properties. A detailed review of the electrical and optical properties of polyimides can be found in Ref. 62. Electrical properties of polyimides were primarily investigated in view of their low dielectric constants and insulating properties. Figure 14 shows the dependence of electrical conductivity of vapor deposited and... 

Chang C-C, Chen W-C (2002) Synthesis and optical properties of polyimide-silica hybrid thin films. Chem Mater 14(10) 4242-4248... 

Ttunmalieh MJ, Zihlif AM (2010) Optical properties of polyimide/silica nanocomposite. Physica B Craidensed Matter 405(23) 4750-4754... 

Cold phosgenation, 222 Color contamination, 541 Colorless polyimides, optical properties of, 277-279... 

Optical properties, of colorless polyimides, 277-279 Optical rotation, 490 Opto-electronic targets, 271-272 Organic phase-soluble aromatic polyesters, 77... 

Optical properties of the material are less critical for microchips hyphenated with MS than for devices with on-chip optical detection where low background absorption or fluorescence is mandatory. Thus, completely opaque polymers like glassy carbon or polyimide " can be used as microfabrication substrates. Furthermore, polymer microchips are of great interest because their potentially low manufacturing costs may allow them to be disposable. Methods used for the fabrication of plastic chips include laser ablation and molding methods. 

Table 14.5 lists the thermal, electrical, and optical properties of perfluorinated polyimides, along with those of partially fluorinated and unfluorinated polyimides. Because of die flexible structure of the lOFEDA component, the polymer decomposition temperatures and values of perfluorinated polyimides are slightly lower than those of conventional polyimides. This coincides with the results of Hougham et al. who reported that an increase in fluorine content in... 

Table 14.5. Thermal, Electrical, and Optical Properties of Perfluorinated, Partially Fluorinated, and Unfluorinated Polyimides...

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. ... 

PFMB can be used to prepare aromatic polyimides that display solubility in ketone, ether, and polar aprotic solvents. This unusual solubility can be utilized in die facile preparation of thin films that display anisotropy in their structures and properties. The anisotropy in the optical properties of the films makes them promising candidates for use as compensation layers in liquid-crystal displays. Their low dielectric constants and CTEs in combination with their outstanding thennal and thermooxidative stabilities make diem candidates for dielectric layers in microelectronics applications. 

Table II Linear Optical Properties of Several Aromatic Polyimides Based on the...

The optical properties of a polyimide-aramid can be improved by the addition of silica. A high silica... 

Jang et al. [85] prepared a highly kinked diamine (3-31 in Table 3.3), a fluorinated diamine (3-32 in Table 3.3), and a biphenyl based-fluorinated diamine (3-33 in Table 3.3) and studied the color intensity and optical properties of the synthesized polyimides. Introduction of kink structures disrupted effective CTC formation, leading to colorless polyimide films with high transmittance. Wang et al. [86] developed meta-diamine, namely 4,4 -/ /s (3-amino-5-trifluoro-methylphenoxy) biphenyl (3-34 in Table 3.3), with the aim of improving the melt processability and solubility of the polyimides. Shao et al. [87] designed a -CF3-substituted unsymmetrical diamine (3-35... 

M. He, Y. Zhou, J. Dai, R. Liu, Y. Cui, T. Zhang, Synthesis and nonlinear optical properties of soluble fluorinated polyimides containing hetarylazo chromophores with large hyperpolarizability, Polymer50(16) (2009) 3924-3931. 

W. Jang, D. Shin, S. Choi, S. Park, H. Han, Effects of internal linkage groups of fluorinated diamine on the optical and dielectric properties of polyimide thin films. Polymer 48 (7)(2007) 2130-2143. 

Koiznmi S., Matsnda S.-L, and Ando S. Synthesis, characterization, and optical properties of nniaxiaUy drawn and gold nanoparticle dispersed fluorinated polyimide films. J. Photopolym. Sci. Technol. 15 no. 2 (2002) 231-236. 

The observed optical properties of chiral nematic films depend critically on the direction of the director at the surface interface and on how this propagates to the bulk material. If the director is oriented along the surface of the cell using suitable alignment agents, such as rubbed polyimide, PVA, or PTFE, then the helix axis direction (see Fig. 1) is perpendicular to the substrates, as shown in Fig. 2 a. In this case, an optically active transparent planar texture is obtained. It is this texture that is normally used to observe the bright iridescent reflection colors initially observed by Reinitzer and Leh-... 

We have made measurements of the electro-optical properties of the MIS devices fabricated with PMMA and with polyimide. We show in figure 34 the spectrally-resolved response for the device with PMMA previously characterised for its electrical response in figure 29. The charge-induced mid-gap absorption is seen here at 0.55 eV this is lower than the 0.8 eV found for the Si(>2-based devices, but at the same energy as the... 

Relatively few processible polyimides, particularly at a reasonable cost and iu rehable supply, are available commercially. Users of polyimides may have to produce iutractable polyimides by themselves in situ according to methods discussed earlier, or synthesize polyimides of unique compositions iu order to meet property requirements such as thermal and thermoxidative stabilities, mechanical and electrical properties, physical properties such as glass-transition temperature, crystalline melting temperature, density, solubility, optical properties, etc. It is, therefore, essential to thoroughly understand the stmcture—property relationships of polyimide systems, and excellent review articles are available (1—5,92). 

Phthalazinone, 355 synthesis of, 356 Phthalic anhydride, 101 Phthalic anhydride-glycerol reaction, 19 Physical properties. See also Barrier properties Dielectric properties Mechanical properties Molecular weight Optical properties Structure-property relationships Thermal properties of aliphatic polyesters, 40-44 of aromatic-aliphatic polyesters, 44-47 of aromatic polyesters, 47-53 of aromatic polymers, 273-274 of epoxy-phenol networks, 413-416 molecular weight and, 3 of PBT, PEN, and PTT, 44-46 of polyester-ether thermoplastic elastomers, 54 of polyesters, 32-60 of polyimides, 273-287 of polymers, 3... 

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